ADVERTISEMENT

bq25601.pdf

Ogniwo 18650 zamiast baterii w router huawei E5372s-32

Stoczyłem nierówny bój z wyszukiwarkami, Amazonem i chińskimi platformami sprzedażowymi, lecz informacji o zawartości pakietu zasilającego nie znalazłem. Rozpocząłem poszukiwania do drugiej strony, czyli od nazwy urządzenia, w którym akumulator jest stosowany. Udało się znaleźć stronę z opisem rozbiórki modemu Link. Na jednym ze zdjęć pojawił się układ BQ25601. Szybki przeskok na stronę Texas Instruments, wyszukanie dokumentacji, w której jest schemat i informacja o trzeciej nodze. :D UWAGA - trzecia noga,to wyprowadzenie termistora od masy, czyli od minusa akumulatora. UWAGA2 - termistor ma oporność 10 kΩ. Także pomiar omomierzem na zakresie 20 kΩ potwierdził doniesienia inżynierów firmy Texas Instruments. Szybko sprawdziłem swój pakiet BH434666 i w nim też jest termistor o oporności 9 kΩ w temperaturze 25° C. Zawartość pakietu udało się ustalić (akumulator i termistor). Pora ocenić czy ładowarka w modemie poradzi sobie z większym akumulatorem. Brak termistora nie zatrzyma ładowarki gdy akumulator nagrzeje się nadmiernie. Reszta informacji w dokumentacji układu BQ25601.


Download file - link to post

Order
Now

Product
Folder

Support &
Community

Tools &
Software

Technical
Documents

bq25601
SLUSCK5 – MARCH 2017

2

bq25601 I C Controlled 3-A Single-Cell Battery Charger
for High Input Voltage and Narrow Voltage DC (NVDC) Power Path Management
1 Features


1











High-Efficiency, 1.5-MHz, Synchronous SwitchMode Buck Charger
– 92% Charge Efficiency at 2 A from 5-V Input
– Optimized for USB Voltage Input (5 V)
– Selectable Low Power Pulse Frequency
Modulation (PFM) Mode for Light Load
Operations
Supports USB On-The-Go (OTG)
– Boost Converter With Up to 1.2-A Output
– 92% Boost Efficiency at 1-A Output
– Accurate Constant Current (CC) Limit
– Soft-Start Up To 500-µF Capacitive Load
– Output Short Circuit Protection
– Selectable Low Power PFM Mode for Light
Load Operations
Single Input to Support USB Input and High
Voltage Adapters
– Support 3.9-V to 13.5-V Input Voltage Range
With 22-V Absolute Maximum Input Voltage
Rating
– Programmable Input Current Limit (100 mA to
3.2 A With 100-mA Resolution) to Support
USB 2.0, USB 3.0 Standards and High Voltage
Adaptors (IINDPM)
– Maximum Power Tracking by Input Voltage
Limit Up to 5.4 V (VINDPM)
– VINDPM Threshold Automatically Tracks
Battery Voltage
– Auto Detect USB SDP, DCP and NonStandard Adaptors
High Battery Discharge Efficiency With 19.5-mΩ
Battery Discharge MOSFET
Narrow VDC (NVDC) Power Path Management
– Instant-On Works with No Battery or Deeply
Discharged Battery
– Ideal Diode Operation in Battery Supplement
Mode
BATFET Control to Support Ship Mode, Wake Up
and Full System Reset
Flexible Autonomous and I2C Mode for Optimal






System Performance
High Integration Includes All MOSFETs, Current
Sensing and Loop Compensation
High Accuracy
– ±0.5% Charge Voltage Regulation
– ±5% at 1.5-A Charge Current Regulation
Create a Custom Design Using the bq25601 With
the WEBENCH® Power Designer

2 Applications



Smart Phones
Portable Internet Devices and Accessory

3 Description
The bq25601 device is a highly-integrated 3-A switchmode battery charge management and system power
path management device for single cell Li-Ion and Lipolymer battery. The low impedance power path
optimizes switch-mode operation efficiency, reduces
battery charging time and extends battery life during
discharging phase. The I2C serial interface with
charging and system settings makes the device a
truly flexible solution.
Device Information(1)
PART NUMBER
bq25601

PACKAGE
WQFN (24)

BODY SIZE (NOM)
4.00 mm × 4.00 mm

(1) For all available packages, see the orderable addendum at
the end of the data sheet.

Simplified Application
USB

VBUS

BTST

2

I C Bus
Host

SW

SYS

Host Control

BAT

ICHG

REGN

+

QON
Optional
TS

1

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.

bq25601
SLUSCK5 – MARCH 2017

www.ti.com

Table of Contents
1
2
3
4
5
6
7

Features ..................................................................
Applications ...........................................................
Description .............................................................
Revision History.....................................................
Description (continued).........................................
Pin Configuration and Functions .........................
Specifications.........................................................
7.1
7.2
7.3
7.4
7.5
7.6

8

8.3 Feature Description................................................. 16
8.4 Register Maps ......................................................... 31

1
1
1
2
3
4
6

9

Application and Implementation ........................ 42
9.1 Application information............................................ 42
9.2 Typical Application Diagram .................................. 43

10 Power Supply Recommendations ..................... 45
11 Layout................................................................... 46
11.1 Layout Guidelines ................................................. 46
11.2 Layout Example .................................................... 46

Absolute Maximum Ratings ...................................... 6
ESD Ratings.............................................................. 6
Recommended Operating Conditions....................... 6
Thermal information .................................................. 7
Electrical Characteristics........................................... 7
Typical Characteristics ............................................ 12

12 Device and Documentation Support ................. 48
12.1
12.2
12.3
12.4
12.5

Detailed Description ............................................ 14
8.1 Overview ................................................................. 14
8.2 Functional Block Diagram ....................................... 15

Documentation Support .......................................
Community Resources..........................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................

48
48
48
48
48

13 Mechanical, Packaging, and Orderable
Information ........................................................... 49

4 Revision History
DATE

2

REVISION

NOTES

March 2017

*

Initial release.

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

bq25601
www.ti.com

SLUSCK5 – MARCH 2017

5 Description (continued)
The bq25601 is a highly-integrated 3.0-A switch-mode battery charge management and system power path
management device for single cell Li-Ion and Li-polymer battery. It features fast charging with high input voltage
support for a wide range of smart phones, tablets and portable devices. Its low impedance power path optimizes
switch-mode operation efficiency, reduces battery charging time and extends battery life during discharging
phase. Its input voltage and current regulation deliver maximum charging power to battery. The solution is highly
integrated with input reverse-blocking FET (RBFET, Q1), high-side switching FET (HSFET, Q2), low-side
switching FET (LSFET, Q3), and battery FET (BATFET, Q4) between system and battery. It also integrates the
bootstrap diode for the high-side gate drive for simplified system design. The I2C serial interface with charging
and system settings makes the device a truly flexible solution.
The device supports a wide range of input sources, including standard USB host port, USB charging port, and
USB compliant high voltage adapter. The device sets default input current limit based on the built-in USB
interface. To set the default input current limit, the device takes the result from detection circuit in the system,
such as USB PHY device. The device is compliant with USB 2.0 and USB 3.0 power spec with input current and
voltage regulation. The device also meets USB On-the-Go (OTG) operation power rating specification by
supplying 5.15 V on VBUS with constant current limit up to 1.2A.
The power path management regulates the system slightly above battery voltage but does not drop below 3.5 V
minimum system voltage (programmable). With this feature, the system maintains operation even when the
battery is completely depleted or removed. When the input current limit or voltage limit is reached, the power
path management automatically reduces the charge current to zero. As the system load continues to increase,
the power path discharges the battery until the system power requirement is met. This Supplement Mode
prevents overloading the input source.
The device initiates and completes a charging cycle without software control. It senses the battery voltage and
charges the battery in three phases: pre-conditioning, constant current and constant voltage. At the end of the
charging cycle, the charger automatically terminates when the charge current is below a preset limit and the
battery voltage is higher than recharge threshold. If the fully charged battery falls below the recharge threshold,
the charger automatically starts another charging cycle.
The charger provides various safety features for battery charging and system operations, including battery
negative temperature coefficient thermistor monitoring, charging safety timer and overvoltage and overcurrent
protections. The thermal regulation reduces charge current when the junction temperature exceeds 110°C
(programmable). The STAT output reports the charging status and any fault conditions. Other safety features
include battery temperature sensing for charge and boost mode, thermal regulation and thermal shutdown and
input UVLO and overvoltage protection. The VBUS_GD bit indicates if a good power source is present. The INT
output Immediately notifies host when fault occurs.
The device also provides QON pin for BATFET enable and reset control to exit low power ship mode or full
system reset function.
The device is available in 24-pin, 4 mm × 4 mm x 0.75 mm thin WQFN package.

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

3

bq25601
SLUSCK5 – MARCH 2017

www.ti.com

6 Pin Configuration and Functions

VBUS

PMID

REGN

BTST

SW

SW

24

23

22

21

20

19

RTW Package
24-Pin WQFN
Top View

VAC

1

18

GND

PSEL

2

17

GND

PG

3

16

SYS

STAT

4

15

SYS

SCL

5

14

BAT

SDA

6

13

BAT

9

10 11 12

NC

CE

NC

QON

8

TS

7
INT

Thermal
Pad

(Not to scale)

Pin Functions
Pin
NAME

NO.
13

TYPE (1)

DESCRIPTION

P

Battery connection point to the positive terminal of the battery pack. The internal BATFET and current sensing is
connected between SYS and BAT. Connect a 10 µF close to the BAT pin.

21

P

PWM high side driver positive supply. Internally, the BTST pin is connected to the cathode of the boost-strap
diode. Connect the 0.047-μF bootstrap capacitor from SW to BTST.

9

BAT

DI

Charge enable pin. When this pin is driven low, battery charging is enabled.



Ground pins.

DO

Open-drain interrupt Output. Connect the INT to a logic rail through 10-kΩ resistor. The INT pin sends an active
low, 256-µs pulse to host to report charger device status and fault.



No Connect. Keep the pins float.

14

BTST
CE
GND
INT

17
18
7
8

NC

10

PG

3

DO

Open drain active low power good indicator. Connect to the pull up rail through 10-kΩ resistor. LOW indicates a
good input source if the input voltage is between UVLO and ACOV, above SLEEP mode threshold, and current
limit is above 30 mA.

PMID

23

DO

Connected to the drain of the reverse blocking MOSFET (RBFET) and the drain of HSFET. Put 10 μF ceramic
capacitor on PMID to GND.

PSEL

2

DI

Power source selection input. Set 500 mA input current limit by pulling this pin high and set 2.4A input current limit
by pulling this pin low. Once the device gets into host mode, the host can program different input current limits to
IINDPM register.

QON

12

DI

BATFET enable/reset control input. When BATFET is in ship mode, a logic low of tSHIPMODE duration turns on
BATFET to exit shipping mode. When VBUS is not pluggeD–in, a logic low of tQON_RST (minimum 8 s) duration
resets SYS (system power) by turning BATFET off for tBATFET_RST (minimum 250 ms) and then re-enable BATFET
to provide full system power reset. The pin contains an internal pull-up to maintain default high logic.

REGN

22

P

LSFET driver and internal supply output. Internally, REGN is connected to the anode of the boost-strap diode.
Connect a 4.7-μF (10-V rating) ceramic capacitor from REGN to GND. The capacitor should be placed close to the
IC.

SCL

5

DI

I2C interface clock. Connect SCL to the logic rail through a 10-kΩ resistor.

SDA

6

DIO

I2C interface data. Connect SDA to the logic rail through a 10-kΩ resistor.

(1)
4

AI = Analog input, AO = Analog Output, AIO = Analog input Output, DI = Digital input, DO = Digital Output, DIO = Digital input Output, P
= Power
Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

bq25601
www.ti.com

SLUSCK5 – MARCH 2017

Pin Functions (continued)
Pin
NAME

STAT

SW

SYS

NO.

4

19
20
15
16

TYPE (1)

DO

DESCRIPTION
Open-drain charge status output. Connect the STAT pin to a logic rail via 10-kΩ resistor. The STAT pin indicates
charger status. Collect a current limit resister and a LED from a rail to this pin.
Charge in progress: LOW
Charge complete or charger in SLEEP mode: HIGH
Charge suspend (fault response): 1-Hz, 50% duty cycle Pulses
This pin can be disabled via EN_ICHG_MON[1:0] register bits.

P

Switching node output. Connected to output inductor. Connect the 0.047-μF bootstrap capacitor from SW to BTST.

P

Converter output connection point. The internal current sensing network is connected between SYS and BAT.
Connect a 20 µF capacitor close to the SYS pin.

TS

11

AI

Temperature qualification voltage input to support JEITA profile. Connect a negative temperature coefficient
thermistor. Program temperature window with a resistor divider from REGN to TS to GND. Charge suspends when
TS pin is out of range. When TS pin is not used, connect a 10-kΩ resistor from REGN to TS and connect a 10-kΩ
resistor from TS to GND. It is recommended to use a 103AT-2 thermistor.

VAC

1

AI

Charge input voltage sense. This pin must be connected to VBUS pin.

VBUS

24

P

Charger input. The internal n-channel reverse block MOSFET (RBFET) is connected between VBUS and PMID
pins. Place a 1-uF ceramic capacitor from VBUS to GND close to device.

Thermal Pad



P

Thermal pad and ground reference. This pad is ground reference for the device and it is also the thermal pad used
to conduct heat from the device. This pad should be tied externally to a ground plane through PCB vias under the
pad.

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

5

bq25601
SLUSCK5 – MARCH 2017

www.ti.com

7 Specifications
7.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted) (1)
MIN

MAX

UNIT

VAC, VBUS (converter not switching) (2)

–2

22

V

Voltage Range (with respect to
GND)

BTST, PMID (converter not switching) (2)

–0.3

22

V

Voltage Range (with respect to
GND)

SW

–2

16

V

BTST to SW

–0.3

7

V

PSEL

–0.3

7

V

Voltage Range (with respect to
GND)

REGN, TS, CE, PG, BAT, SYS (converter not switching)

–0.3

7

V

Output Sink Current

STAT

6

mA

Voltage Range (with respect to
GND)

SDA, SCL, INT, /QON, STAT

–0.3

7

V

Voltage Range (with respect to
GND)

PGND to GND (QFN package only)

–0.3

0.3

V

Output Sink Current

INT

6

mA

Operating junction temperature, TJ

–40

150

°C

Storage temperature, Tstg

–65

150

°C

Voltage Range (with respect to
GND)

Voltage Range (with respect to
GND)
Voltage Range (with respect to
GND)

(1)

(2)

Stresses beyond those listed under Absolute maximum Ratings may cause permanent damage to the device. These are stress ratings
only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended
Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. All voltage
values are with respect to the network ground terminal unless otherwise noted.
VBUS is specified up to 22 V for a maximum of one hour at room temperature

7.2 ESD Ratings
VALUE
Human body model (HBM), per
ANSI/ESDA/JEDEC JS-001, all pins (1)
V(ESD)

(1)
(2)

Electrostatic discharge

±2000

Charged device model (CDM), per
JEDEC specification JESD22-C101, all
pins (2)

UNIT

±250

V

JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.

7.3 Recommended Operating Conditions
MIN
VBUS
Iin

Input current (VBUS)

ISWOP

Output current (SW)

VBATOP

Battery voltage

IBATOP

Fast charging current

IBATOP

Discharging current (continuous)

TA

Operating ambient temperature

(1)

6

NOM

3.9

MAX

UNIT

13.5 (1)

V

3.25

Input voltage

A

3.25

A

4.624

V

3.0

A

6
–40

A

85

°C

The inherent switching noise voltage spikes should not exceed the absolute maximum voltage rating on either the BTST or SW pins. A
tight layout minimizes switching noise.

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

bq25601
www.ti.com

SLUSCK5 – MARCH 2017

7.4 Thermal information
bq25601
THERMAL METRIC (1)

RTW (WQFN)

UNIT

24 PinS
RθJA

Junction-to-ambient thermal resistance

35.6

°C/W

RθJC(top)

Junction-to-case (top) thermal resistance

22.7

°C/W

RθJB

Junction-to-board thermal resistance

11.9

°C/W

ΨJT

Junction-to-top characterization parameter

0.2

°C/W

ΨJB

Junction-to-board characterization parameter

12

°C/W

RθJC(bot)

Junction-to-case (bottom) thermal resistance

2.6

°C/W

(1)

For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report, SPRA953.

7.5 Electrical Characteristics
VVAC_UVLOZ & lt; VVAC & lt; VVAC_OV and VVAC & gt; VBAT + VSLEEP, TJ = –40°C to 125°C and TJ = 25°C for typical values (unless
otherwise noted)
PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNIT

QUIESCENT CURRENTS
IBAT

Battery discharge current (BAT,
SW, SYS) in buck mode

VBAT = 4.5 V, VBUS & lt; VAC-UVLOZ,
leakage between BAT and VBUS,
TJ & lt; 85°C

IBAT

Battery discharge current (BAT)
in buck mode

VBAT = 4.5 V, HIZ Mode and
OVPFET_DIS = 1 or No VBUS, I2C
disabled, BATFET Disabled. TJ & lt;
85°C

IBAT

Battery discharge current (BAT,
SW, SYS)

VBAT = 4.5 V, HIZ Mode and
OVPFET_DIS = 1 or No VBUS, I2C
Disabled, BATFET Enabled. TJ & lt;
85°C

IVBUS_HIZ

Input supply current (VBUS) in
buck mode

VVBUS = 5 V, High-Z Mode and
OVPFET_DIS = 1, No battery

IVBUS_HIZ

Input supply current (VBUS) in
buck mode

IVBUS

5

µA

17

33

µA

58

85

µA

37

50

µA

VVBUS = 12 V, High-Z Mode and
OVPFET_DIS = 1, No battery

68

90

µA

Input supply current (VBUS) in
buck mode

VVBUS = 12 V, VVBUS & gt; VVBAT,
converter not switching

1.5

3

mA

IVBUS

Input supply current (VBUS) in
buck mode

VVBUS & gt; VUVLO, VVBUS & gt; VVBAT,
converter switching, VBAT = 3.8V,
ISYS = 0A

3

mA

IBOOST

Battery Discharge Current in
boost mode

VBAT = 4.2 V, boost mode, IVBUS = 0
A, converter switching

3

mA

VBUS, VAC AND BAT PIN POWER-UP
VBUS_OP
VVAC_UVLOZ

VBUS operating range
VBUS for active I2C, no battery
Sense VAC pin voltage

VVBUS rising

3.9

13.5

VVAC rising

3.3

3.6

V
V

VVAC_UVLOZ_HYS

I2C active hysteresis

VAC falling from above VVAC_UVLOZ

300

VVAC_PRESENT

One of the conditions to turn on
REGN

VVAC rising

3.65

VVAC_PRESENT_HYS

One of the conditions to turn on
REGN

VVAC falling

500

VSLEEP

Sleep mode falling threshold

(VVAC–VVBAT ), VBUSMIN_FALL ≤ VBAT
≤ VREG, VAC falling

15

60

110

mV

VSLEEPZ

Sleep mode rising threshold

(VVAC–VVBAT ), VBUSMIN_FALL ≤ VBAT
≤ VREG, VAC rising

115

220

340

mV

VVAC_OV_RISE

VAC 6.5-V Overvoltage rising
threshold

VAC rising; OVP (REG06[7:6]) = '01'

6.1

6.4

6.7

V

mV
3.9

mV

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

V

7

bq25601
SLUSCK5 – MARCH 2017

www.ti.com

Electrical Characteristics (continued)
VVAC_UVLOZ & lt; VVAC & lt; VVAC_OV and VVAC & gt; VBAT + VSLEEP, TJ = –40°C to 125°C and TJ = 25°C for typical values (unless
otherwise noted)
PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNIT

VAC rising, OVP (REG06[7:6]) = '10'

10.35

10.9

11.5

V

VAC 14-V Overvoltage rising
threshold

VAC rising, OVP (REG06[7:6]) = '11'

13.5

14.2

14.85

V

VVAC_OV_HYS

VAC 6.5-V Overvoltage
hysteresis

VAC falling, OVP (REG06[7:6]) =
'01'

320

mV

VVAC_OV_HYS

VAC 10.5-V Overvoltage
hysteresis

VAC falling, OVP (REG06[7:6]) =
'10'

250

mV

VVAC_OV_HYS

VAC 14-V Overvoltage hysteresis

VAC falling, OVP (REG06[7:6]) =
'11'

300

mV

VVAC_OV_RISE

VAC 10.5-V Overvoltage rising
threshold

VVAC_OV_RISE

2

VBAT_UVLOZ

BAT for active I C, no adapter

VBAT rising

2.5

VBAT_DPL_FALL

Battery Depletion Threshold

VBAT falling

2.2

2.6

V
V

VBAT_DPL_RISE

Battery Depletion Threshold

VBAT rising

2.35

2.8

V

VBAT_DPL_HYST

Battery Depletion rising
hysteresis

VBAT rising

VBUSMIN_FALL

Bad adapter detection falling
threshold

VBUS falling

VBUSMIN_HYST

Bad adapter detection hysteresis

IBADSRC

Bad adapter detection current
source

Sink current from VBUS to GND

VSYS_MIN

System regulation voltage

VVBAT & lt; SYS_MIN[2:0] = 101,
BATFET Disabled (REG07[5] = 1)

VSYS

System Regulation Voltage

ISYS = 0 A, VVBAT & gt; VSYSMIN, VVBAT
= 4.400 V, BATFET disabled
(REG07[5] = 1)

VSYS_MAX

Maximum DC system voltage
output

ISYS = 0 A, , Q4 off, VVBAT≤ 4.400 V,
VVBAT & gt; VSYSMIN = 3.5V

RON(RBFET)

Top reverse blocking MOSFET
on-resistance between VBUS and -40°C≤ TA ≤ 125°C
PMID - Q1

45



RON(HSFET)

Top switching MOSFET onresistance between PMID and
SW - Q2

VREGN = 5 V , -40°C≤ TA ≤ 125°C

62



RON(LSFET)

Bottom switching MOSFET onresistance between SW and GND VREGN = 5 V , -40°C≤ TA ≤ 125°C
- Q3

71



VFWD

BATFET forward voltage in
supplement mode

30

mV

RON(BAT-SYS)

SYS-BAT MOSFET on-resistance

QFN package, Measured from BAT
to SYS, VBAT = 4.2V, TJ = 25°C

19.5

24



RON(BAT-SYS)

QFN package, Measured from BAT
SYS-BAT MOSFET on-resistance to SYS, VBAT = 4.2V, TJ = –40 125°C

19.5

30



180
3.75

3.9

mV
4.0

V

80

mV

30

mA

POWER-PATH
3.5

V

VBAT +
50 mV
4.4

3.68

V

4.45

4.48

V

BATTERY CHARGER
VBATREG_RANGE

Charge voltage program range

VBATREG_STEP

Charge voltage step

VBATREG

VBATREG_ACC

8

Charge voltage setting

Charge voltage setting accuracy

3.856

4.624
32

V
mV

VREG (REG04[7:3]) = 4.208 V
(01011), V, –40 ≤ TJ ≤ 85°C

4.187

4.208

4.229

V

VREG (REG04[7:3]) = 4.352 V
(01111), V, –40 ≤ TJ ≤ 85°C

4.330

4.352

4.374

V

VBAT = 4.208 V or VBAT = 4.352 V,
–40 ≤ TJ ≤ 85°C

Submit Documentation Feedback

–0.5%

0.5%

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

bq25601
www.ti.com

SLUSCK5 – MARCH 2017

Electrical Characteristics (continued)
VVAC_UVLOZ & lt; VVAC & lt; VVAC_OV and VVAC & gt; VBAT + VSLEEP, TJ = –40°C to 125°C and TJ = 25°C for typical values (unless
otherwise noted)
PARAMETER
ICHG_REG_RANGE
ICHG_REG_STEP

TEST CONDITIONS

Charge current regulation range

MIN

Charge current regulation step

TYP

MAX

UNIT

3000

0

mA

60

ICHG_REG

Charge current regulation setting

ICHG = 240 mA, VVBAT = 3.1V or
VVBAT = 3.8 V

ICHG_REG_ACC

Charge current regulation
accuracy

ICHG = 240 mA, VVBAT = 3.1 V or
VVBAT = 3.8 V

ICHG_REG

Charge current regulation setting

ICHG = 720 mA, VVBAT = 3.1 V or
VVBAT = 3.8 V

ICHG_REG

Charge current regulation
accuracy

ICHG_REG = 720 mA, VBAT = 3.1 V or
VBAT = 3.8 V

ICHG_REG

Charge current regulation setting

ICHG = 1.38 A, VVBAT = 3.1 V or
VVBAT = 3.8 V

1.311

ICHG_REG_ACC

Charge current regulation
accuracy

ICHG = 720 mA or ICHG = 1.38 A,
VVBAT = 3.1 V or VVBAT = 3.8 V

–5%

VBATLOWV_FALL

Battery LOWV falling threshold

ICHG = 240 mA

VBATLOWV_RISE

Battery LOWV rising threshold

IPRECHG

Precharge current regulation

IPRECHG_ACC

Precharge current regulation
accuracy

ITERM

0.216
–10%
0.685

0.24

mA
0.264

A

10%
0.720

-5%

0.755

A

5%
1.380

1.449

A

5%

2.7

2.8

2.9

Pre-charge to fast charge

3.0

3.12

3.24

V

IPRECHG[3:0] = '0010' = 180 mA

153

171

189

mA

IPRECHG[3:0] = '0010' = 180 mA

–15

5

%

Termination current regulation

ICHG & gt; 780 mA, ITERM[3:0] = '0010'
= 180 mA, VVBAT = 4.208 V

150

216

mA

ITERM_ACC

Termination current regulation
accuracy

ICHG & gt; 780 mA, , ITERM[3:0] =
'0010' = 180 mA, VVBAT = 4.208 V

ITERM

Termination current regulation

ICHG ≤ 780 mA, , ITERM[3:0] =
'0010' = 180 mA

162

ITERM_ACC

Termination current regulation
accuracy

ICHG ≤ 780 mA, , ITERM[3:0] =
'0010' = 180 mA

-10%

ITERM

Termination current regulation

ICHG = 600 mA, ITERM[3:0] = '0000'
= 60 mA, VVBAT = 4.208 V

ITERM_ACC

Termination current regulation
accuracy

ICHG = 600 mA, ITERM[3:0] = '0000'
= 60 mA, VVBAT = 4.208 V

VSHORT

Battery short voltage

VVBAT falling

1.85

2

2.15

V

VSHORTZ

Battery short voltage

VVBAT rising

2.15

2.25

2.35

V

ISHORT

Battery short current

VVBAT & lt; VSHORTZ

70

90

110

mA

VRECHG

Recharge Threshold below
VBAT_REG

VBAT falling, REG04[0] = 0

90

120

150

mV

VRECHG

Recharge Threshold below
VBAT_REG

VBAT falling, REG04[0] = 1

200

230

265

mV

ISYSLOAD

System discharge load current

VSYS = 4.2 V

180

-16.7%

45

V

20%
180

192

mA

10%
60

–25%

75

mA

25%

30

mA

INPUT VOLTAGE AND CURRENT REGULATION
VINDPM

Input voltage regulation limit

VINDPM_ACC

Input voltage regulation accuracy

VINDPM

Input voltage regulation limit

VINDPM_ACC

Input voltage regulation accuracy

VDPM_VBAT

Input voltage regulation limit
tracking VBAT

VDPM_VBAT_ACC

VINDPM (REG06[3:0] = 0000) = 3.9 V

Input voltage regulation accuracy
tracking VBAT

3.78

3.95

–3%
VINDPM (REG06[3:0] = 0110) = 4.4 V

4.268

VINDPM = 3.9V,
VDPM_VBAT_TRACK = 300mV,
VBAT = 4.0V

4.171

4.4

4.532

4.3

4.43

–3%

–3%

4.1

Product Folder Links: bq25601

V

3%
V

3%

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

V

5%

9

bq25601
SLUSCK5 – MARCH 2017

www.ti.com

Electrical Characteristics (continued)
VVAC_UVLOZ & lt; VVAC & lt; VVAC_OV and VVAC & gt; VBAT + VSLEEP, TJ = –40°C to 125°C and TJ = 25°C for typical values (unless
otherwise noted)
PARAMETER

TEST CONDITIONS

MAX

UNIT

450

500

mA

VVBUS = 5 V, current pulled from
SW, IINDPM (REG[4:0] = 01000) =
900 mA, –40 ≤ TJ ≤ 85°C

750

900

mA

VVBUS = 5 V, current pulled from
SW, IINDPM (REG[4:0] = 01110) =
1.5 A, –40 ≤ TJ ≤ 85°C

1.3

1.5

A

VVBUS = 5 V, current pulled from
SW, IINDPM (REG[4:0] = 00100) =
500 mA, –40 ≤ TJ ≤ 85°C
IINDPM

USB input current regulation limit

IIN_START

MIN

Input current limit during system
start-up sequence

TYP

200

mA

BAT PIN OVERVOLTAGE PROTECTION
VBATOVP_RISE

Battery overvoltage threshold

VBAT rising, as percentage of
VBAT_REG

103

104

105

%

VBATOVP_FALL

Battery overvoltage threshold

VBAT falling, as percentage of
VBAT_REG

101

102

103

%

THERMAL REGULATION AND THERMAL SHUTDOWN
TJUNCTION_REG

Junction Temperature Regulation
Threshold

Temperature Increasing, TREG
(REG05[1] = 1) = 110℃

TJUNCTION_REG

Junction Temperature Regulation
Threshold

Temperature Increasing, TREG
(REG05[1] = 0) = 90℃

TSHUT

Thermal Shutdown Rising
Temperature

Temperature Increasing

TSHUT_HYST

Thermal Shutdown Hysteresis

110

°C

90

°C

160

°C

30

°C

JEITA Thermistor Comparator (BUCK MODE)
VT1

T1 (0°C) threshold, Charge
suspended T1 below this
temperature.

Charger suspends charge. As
Percentage to VREGN

VT1

Falling

72.4%

73.3%

74.2%

As Percentage to VREGN

69%

71.5%

74%

VT2

T2 (10°C) threshold, Charge back
to ICHG/2 and 4.2 V below this
As percentage of VREGN
temperature

67.2%

68%

69%

VT2

Falling

As Percentage to VREGN

66%

66.8%

67.7%

VT3

T3 (45°C) threshold, charge back
to ICHG and 4.05V above this
temperature.

Charger suspends charge. As
Percentage to VREGN

43.8%

44.7%

45.8%

VT3

Falling

As Percentage to VREGN

45.1%

45.7%

46.2%

VT5

T5 (60°C) threshold, charge
suspended above this
temperature.

As Percentage to VREGN

33.7%

34.2%

35.1%

VT5

Falling

As Percentage to VREGN

34.5%

35.3%

36.2%

COLD OR HOT THERMISTER COMPARATOR (BOOST MODE)
VBCOLD

Cold Temperature Threshold, TS
pin Voltage Rising Threshold

As Percentage to VREGN (Approx.
-20°C w/ 103AT), TJ = –20°C 125°C

79.5%

80%

80.5%

VBCOLD

Falling

TJ = –20°C - 125°C

78.5%

79%

79.5%

VBHOT

Hot Temperature Threshold, TS
pin Voltage falling Threshold

As Percentage to VREGN (Approx.
60°C w/ 103AT), TJ = –20°C - 125°C

30.2%

31.2%

32.2%

VBHOT

Rising

TJ = –20°C - 125°C

33.8%

34.4%

34.9%

10

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

bq25601
www.ti.com

SLUSCK5 – MARCH 2017

Electrical Characteristics (continued)
VVAC_UVLOZ & lt; VVAC & lt; VVAC_OV and VVAC & gt; VBAT + VSLEEP, TJ = –40°C to 125°C and TJ = 25°C for typical values (unless
otherwise noted)
PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNIT

CHARGE OVERCURRENT COMPARATOR (CYCLE-BY-CYCLE)
IHSFET_OCP

HSFET cycle-by-cycle overcurrent threshold

5.2

IBATFET_OCP

System over load threshold

6.0

8.0

A
A

CHARGE UNDER-CURRENT COMPARATOR (CYCLE-BY-CYCLE)
VLSFET_UCP

LSFET under-current falling
threshold

From sync mode to non-sync mode

160

mA

PWM
fSW

PWM switching frequency

DMAX

Oscillator frequency, buck mode

1320

1500

1680

kHz

Oscillator frequency, boost mode

1150

1412

1660

kHz

5.280

V

3

%

Maximum PWM duty cycle (1)

97%

BOOST MODE OPERATION
VOTG_REG

Boost mode regulation voltage

VVBAT = 3.8 V, I(PMID) = 0 A,
BOOSTV[1:0] = '10' = 5.15 V

4.972

VOTG_REG_ACC

Boost mode regulation voltage
accuracy

VVBAT = 3.8 V, I(PMID) = 0 A,
BOOSTV[1:0] = '10' = 5.15 V

-3

VVBAT falling, MIN_VBAT_SEL
(REG01[0]) = 0

2.6

2.8

2.9

V

VVBAT rising, MIN_VBAT_SEL
(REG01[0]) = 0

2.9

3.0

3.15

V

VVBAT falling, MIN_VBAT_SEL
(REG01[0]) = 1

2.4

2.5

2.6

V

VVBAT rising, MIN_VBAT_SEL
(REG01[0]) = 1

2.7

2.8

2.9

V

1.4

1.6

A

0.722

A

6.15

V

VBATLOWV_OTG

Battery voltage exiting boost
mode

IOTG

OTG mode output current

BOOST_LIM (REG02[7]) = 1

1.2

IOTG_OCP_ACC

Boost mode RBFET over-current
protection accuracy

BOOST_LIM = 0.5 A (REG02[7] = 0)

0.5

VOTG_OVP

OTG overvoltage threshold

Rising threshold

IOTG_HSZCP

HSFET under current falling
threshold

5.126

5.55

5.8
100

mA

REGN LDO
VREGN

REGN LDO output voltage

VVBUS = 9V, IREGN = 40mA

5.6

6

6.55

V

VREGN

REGN LDO output voltage

VVBUS = 5V, IREGN = 20mA

4.6

4.7

4.8

V

0.4

V

LOGIC I/O PIN CHARACTERISTICS (CE, PSEL, SCL, SDA,, INT)
VILO

Input low threshold CE

VIH

Input high threshold CE

IBIAS

High-level leakage current CE

VILO

Input low threshold PSEL

VIH

Input high threshold PSEL

IBIAS

High-level leakage current PSEL

1.3
Pull up rail 1.8 V

V
1

µA

0.4

V

1.3
Pull up rail 1.8V

V
1

µA

0.4

V

LOGIC I/O PIN CHARACTERISTICS (PG, STAT)
VOL
(1)

Low-level output voltage
Specified by design. Not production tested.

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

11

bq25601
SLUSCK5 – MARCH 2017

www.ti.com

7.6 Typical Characteristics
100

95

95

90

90
Efficiency (%)

Charge Efficiency (%)

100

85
80
75

85
80
75

70

VBUS Voltage
5V
9V
12 V

65
60
0

0.5

1

fSW = 1.5 MHz
VBAT=3.8V

1.5
2
Charge Current (A)

2.5

VBAT = 3.2 V
VBAT = 3.8 V
VBAT = 4.1 V

70
65
0.2

3

0.4

inductor DCR = 18 mΩ

VOTG = 5.15 V

Figure 1. Charge Efficiency vs. Charge Current

1.2

1.4
D001

inductor DCR = 18 mΩ

4

Charge Current Accuracy (%)

6

5

OTG Output Voltage (V)

0.8
1
OTG Current (A)

Figure 2. Efficiency vs. OTG Current

6

4
3
2
1
0
0

0.2

0.4

0.6
0.8
1
Output Current (A)

IOTG = 1.2 A
VVBAT = 3.8 V

1.2

1.4

2
0
-2
-4
-6
-8
0.5

1.6

0.75

1

1.25

D001

1.5 1.75 2 2.25
Charge Current (A)

2.5

2.75

3
D001

VOTG = 5.15 V

Figure 3. OTG Output Voltage vs. Output Current

Figure 4. Charge Current Accuracy
4.5

3.85

VBATREG = 4.208 V
VBATREG = 4.352 V

BATREG Charge Voltage (V)

3.8

SYSMIN Voltage (V)

0.6

D001

3.75
3.7
3.65
3.6

4.4

4.3

4.2

4.1

3.55
3.5
-40

-25

-10

5

20 35 50 65 80
Junction Temperature (°
C)

95

110 125

-25

D001

Figure 5. SYSMIN Voltage vs. Junction Temperature

12

4
-40

-10

5

20 35 50 65 80
Junction Temperature (°
C)

95

110 125
D001

Figure 6. BATREG Charge Voltage vs. Junction
Temperature

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

bq25601
www.ti.com

SLUSCK5 – MARCH 2017

Typical Characteristics (continued)
2

2.5
IINDPM = 0.5 A
IINDPM = 0.9 A
IINDPM = 1.5 A

2.25

1.6

Charge Current (A)

Input Current Limit (A)

2

ICHG = 0.24 A
ICHG = 0.72 A
ICHG = 1.38 A

1.8

1.75
1.5
1.25
1
0.75

1.4
1.2
1
0.8
0.6

0.5

0.4

0.25

0.2

0
-40

-25

-10

5
20
35
50
Junction Temperature (°
C)

65

80

95

0
-40

-25

-10

D001

Figure 7. Input Current Limit vs. Junction Temperature

5

20 35 50 65 80
Junction Temperature (°
C)

95

110 125
D001

Figure 8. Charge Current vs. Junction Temperature

2.25
2

Charge Current (A)

1.75
1.5
1.25
1
0.75
0.5
110 °
C
90 °
C

0.25
0
55

65

75

85
95
105
115
Junction Temperature (°
C)

125

135
D001

Figure 9. Charge Current vs. Junction Temperature

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

13

bq25601
SLUSCK5 – MARCH 2017

www.ti.com

8 Detailed Description
8.1 Overview
The bq25601 device is a highly integrated 3.0-A switch-mode battery charger for single cell Li-Ion and Li-polymer
battery. It includes the input reverse-blocking FET (RBFET, Q1), high-side switching FET (HSFET, Q2), low-side
switching FET (LSFET, Q3), and battery FET (BATFET, Q4), and bootstrap diode for the high-side gate drive.

14

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

bq25601
www.ti.com

SLUSCK5 – MARCH 2017

8.2 Functional Block Diagram

VBUS

PMID
VVBUS_UVLOZ

+

RBFET (Q1)

UVLO

VVBUS

Q1 Gate
Control

±

IIN
VBAT + VSLEEP

+
VVBUS
VVBUS
VVAC_OV

SLEEP

REGN

EN_REGN
REGN
LDO

±
EN_HIZ
+

ACOV

±
BTST

FBO
VVBUS

VBUS_OVP_BOOST

+

VOTG_OVP
±
IQ2
Q2_UCP_BOOST

+
VVBUS

VOTG_HSZCP
±

±

VOTG_BAT

CONVERTER
Control

±

+

BAT

IINDPM

+

±

SW

Q3_OCP_BOOST

+

+
IIN

HSFET (Q2)

IQ3

VINDPM

REGN

BATOVP

104% × V BAT_REG

IC TJ

LSFET (Q3)
±

+
TREG
±

+

±

±

+

+

SYS
VSYSMIN
±

BAT

ILSFET_UCP

VBAT_REG

PGND

IQ2
+

UCP

Q2_OCP

+
IHSFET_OCP

IQ3
±

ICHG

±
EN_HIZ
EN_CHARGE
EN_BOOST

ICHG_REG

VBTST - VSW
REFRESH

+
VBTST_REFRESH
±
SYS
ICHG

VBAT_REG
ICHG_REG

Q4 Gate
Control

BATFET
(Q4)
BAT

IBADSRC
BAD_SRC

REF
DAC

Converter
Control State
Machine

+
IDC
±
IC TJ

TSHUT

+
TSHUT
±

BAT_GD
Input
Source
Detection
PSEL

BAT
+
VBATGD

VQON

±
USB
Adapter

VREG -VRECHG
RECHRG

+
BAT

/QON

±

INT

ICHG
TERMINATION

+
ITERM

CHARGE
CONTROL
STATE
MACHINE

STAT /
IMON

±
VBATLOWV
BATLOWV

+
BAT
bq25601

±
VSHORT
BATSHORT

/PG

SCL

SDA

+

SUSPEND

±

BAT

I2C
Interface

Battery
Sensing
Thermistor

TS

Copyright © 2017, Texas Instruments Incorporated

/CE

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

15

bq25601
SLUSCK5 – MARCH 2017

www.ti.com

8.3 Feature Description
8.3.1 Power-On-Reset (POR)
The device powers internal bias circuits from the higher voltage of VBUS and BAT. When VBUS rises above
VVBUS_UVLOZ or BAT rises above VBAT_UVLOZ , the sleep comparator, battery depletion comparator and BATFET
driver are active. I2C interface is ready for communication and all the registers are reset to default value. The
host can access all the registers after POR.
8.3.2 Device Power Up from Battery without Input Source
If only battery is present and the voltage is above depletion threshold (VBAT_DPL_RISE), the BATFET turns on and
connects battery to system. The REGN stays off to minimize the quiescent current. The low RDSON of BATFET
and the low quiescent current on BAT minimize the conduction loss and maximize the battery run time.
The device always monitors the discharge current through BATFET (Supplement Mode). When the system is
overloaded or shorted (IBAT & gt; IBATFET_OCP), the device turns off BATFET immediately and set BATFET_DIS bit to
indicate BATFET is disabled until the input source plugs in again or one of the methods described in BATFET
Enable (Exit Shipping Mode) is applied to re-enable BATFET.
8.3.3 Power Up from Input Source
When an input source is plugged in, the device checks the input source voltage to turn on REGN LDO and all the
bias circuits. It detects and sets the input current limit before the buck converter is started. The power up
sequence from input source is as listed:
1. Power Up REGN LDO
2. Poor Source Qualification
3. Input Source Type Detection is based on or PSEL to set default input current limit (IINDPM) register or input
source type.
4. Input Voltage Limit Threshold Setting (VINDPM threshold)
5. Converter Power-up
8.3.3.1 Power Up REGN Regulation
The REGN LDO supplies internal bias circuits as well as the HSFET and LSFET gate drive. The REGN also
provides bias rail to TS external resistors. The pull-up rail of STAT can be connected to REGN as well. The
REGN is enabled when all the below conditions are valid:
• VVAC above VVAC_PRESENT
• VVAC above VBAT + VSLEEPZ in buck mode or VBUS below VBAT + VSLEEP in boost mode
• After 220-ms delay is completed
If any one of the above conditions is not valid, the device is in high impedance mode (HIZ) with REGN LDO off.
The device draws less than IVBUS_HIZ from VBUS during HIZ state. The battery powers up the system when
the device is in HIZ.
8.3.3.2 Poor Source Qualification
After REGN LDO powers up, the device confirms the current capability of the input source. The input source
must meet both of the following requirements in order to start the buck converter.
• VBUS voltage below VVAC_OV
• VBUS voltage above VVBUSMIN when pulling IBADSRC (typical 30 mA)
Once the input source passes all the conditions above, the status register bit VBUS_GD is set high and the INT
pin is pulsed to signal to the host. If the device fails the poor source detection, it repeats poor source qualification
every 2 seconds.
8.3.3.3 Input Source Type Detection
After the VBUS_GD bit is set and REGN LDO is powered, the device runs input source detection through or the
PSEL pin. The bq25601 sets input current limit through PSEL pins.

16

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

bq25601
www.ti.com

SLUSCK5 – MARCH 2017

Feature Description (continued)
After input source type detection is completed, an INT pulse is asserted to the host. in addition, the following
registers and pin are changed:
1. Input Current Limit (IINDPM) register is changed to set current limit
2. PG_STAT bit is set
3. VBUS_STAT bit is updated to indicate USB or other input source
The host can over-write IINDPM register to change the input current limit if needed. The charger input current is
always limited by the IINDPM register.
8.3.3.3.1 PSEL Pins Sets Input Current Limit in bq25601

The bq25601 has PSEL pin for input current limit setting to interface with USB PHY. It directly takes the USB
PHY device output to decide whether the input is USB host or charging port. When the device operates in hostcontrol mode, the host needs to IINDET_EN bit to read the PSEL value and update the IINDPM register. When
the device is in default mode, PSEL value updates IINDPM in real time.
Table 1. Input Current Limit Setting from PSEL
Input Detection

PSEL Pin

INPUT CURRENT LIMIT
(ILIM)

VBUS_STAT

USB SDP

High

500 mA

001

Adapter

Low

2.4A

011

8.3.3.4 Input Voltage Limit Threshold Setting (VINDPM Threshold)
The device supports wide range of input voltage limit (3.9 V – 5.4V) for USBThe device's VINDPM is set at 4.5V.
The device supports dynamic VINDPM trackingsettings which tracks the battery voltage. This function can be
enabled via the VDPM_BAT_TRACK[1:0] register bits. When enabled, the actual input voltage limit will be the
higher of the VINDPM register and VBAT + VDPM_BAT_TRACK offset.
8.3.3.5 Converter Power-Up
After the input current limit is set, the converter is enabled and the HSFET and LSFET start switching. If battery
charging is disabled, BATFET turns off. Otherwise, BATFET stays on to charge the battery.
The device provides soft-start when system rail is ramped up. When the system rail is below 2.2 V, the input
current is limited to is to the lower of 200 mA or IINDPM register setting. After the system rises above 2.2 V, the
device limits input current to the value set by IINDPM register.
As a battery charger, the device deploys a highly efficient 1.5 MHz step-down switching regulator. The fixed
frequency oscillator keeps tight control of the switching frequency under all conditions of input voltage, battery
voltage, charge current and temperature, simplifying output filter design.
The device switches to PFM control at light load or when battery is below minimum system voltage setting or
charging is disabled. The PFM_DIS bit can be used to prevent PFM operation in either buck or boost
configuration.
8.3.4 Boost Mode Operation From Battery
The device supports boost converter operation to deliver power from the battery to other portable devices
through USB port. The boost mode output current rating meets the USB On-The-Go 500 mA output requirement.
The maximum output current is up to 1.2 A. The boost operation can be enabled if the conditions are valid:
1. BAT above VOTG_BAT
2. VBUS less than BAT+VSLEEP (in sleep mode)
3. Boost mode operation is enabled (OTG_CONFIG bit = 1)
4. Voltage at TS (thermistor) pin is within acceptable range (VBHOT & lt; VTS & lt; VBCOLD)
5. After 30-ms delay from boost mode enable

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

17

bq25601
SLUSCK5 – MARCH 2017

www.ti.com

During boost mode, the status register VBUS_STAT bits is set to 111, the VBUS output is 5.15 V and the output
current can reach up to 1.2 A, selected through I2C (BOOST_LIM bit). The boost output is maintained when BAT
is above VOTG_BAT threshold.
When OTG is enabled, the device starts up with PFM and later transits to PWM to minimize the overshoot. The
PFM_DIS bit can be used to prevent PFM operation in either buck or boost configuration.
8.3.5 Host Mode and Standalone Power Management
8.3.5.1 Host Mode and Default Mode in bq25601
The bq25601 is a host controlled charger, but it can operate in default mode without host management. in default
mode, the device can be used as an autonomous charger with no host or while host is in sleep mode. When the
charger is in default mode, WATCHDOG_FAULT bit is HIGH. When the charger is in host mode,
WATCHDOG_FAULT bit is LOW.
After power-on-reset, the device starts in default mode with watchdog timer expired, or default mode. All the
registers are in the default settings. During default mode, any change on PSEL pin will make real time IINDPM
register changes.
in default mode, the device keeps charging the battery with default 10-hour fast charging safety timer. At the end
of the 10-hour, the charging is stopped and the buck converter continues to operate to supply system load.
Writing a 1 to the WD_RST bit transitions the charger from default mode to host mode. All the device parameters
can be programmed by the host. To keep the device in host mode, the host has to reset the watchdog timer by
writing 1 to WD_RST bit before the watchdog timer expires (WATCHDOG_FAULT bit is set), or disable watchdog
timer by setting WATCHDOG bits = 00.
When the watchdog timer expires (WATCHDOG_FAULT bit = 1), the device returns to default mode and all
registers are reset to default values except IINDPM, VINDPM, BATFET_RST_EN, BATFET_DLY, and
BATFET_DIS bits.
POR
watchdog timer expired
Reset registers
I2C interface enabled

Host Mode
Start watchdog timer
Host programs registers

Y
I2C Write?

N
Default Mode
Reset watchdog timer
Reset selective registers

Y
WD_RST bit = 1?

N
N

Y
I2C Write?

Y

N
Watchdog Timer
Expired?

Figure 10. Watchdog Timer Flow Chart
8.3.6 Power Path Management
The device accommodates a wide range of input sources from USB, wall adapter, to car charger. The device
provides automatic power path selection to supply the system (SYS) from input source (VBUS), battery (BAT), or
both.
8.3.7 Battery Charging Management
The device charges 1-cell Li-Ion battery with up to 3.0-A charge current for high capacity tablet battery. The 19.5mΩ BATFET improves charging efficiency and minimize the voltage drop during discharging.
18

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

bq25601
www.ti.com

SLUSCK5 – MARCH 2017

8.3.7.1 Autonomous Charging Cycle
With battery charging is enabled (CHG_CONFIG bit = 1 and CE pin is LOW), the device autonomously
completes a charging cycle without host involvement. The device default charging parameters are listed in
Table 2. The host can always control the charging operations and optimize the charging parameters by writing to
the corresponding registers through I2C.
Table 2. Charging Parameter Default Setting
Default Mode

bq25601

Charging voltage

4.208V

Charging current

2.048 A

Pre-charge current

180 mA

Temperature profile

JEITA

Safety timer

A






180 mA

Termination current

10 hours

new charge cycle starts when the following conditions are valid:
Converter starts
Battery charging is enabled (CHG_CONFIG bit = 1 and ICHG register is not 0 mA and CE is low)
No thermistor fault on TS
No safety timer fault
BATFET is not forced to turn off (BATFET_DIS bit = 0)

The charger device automatically terminates the charging cycle when the charging current is below termination
threshold, battery voltage is above recharge threshold, and device not is in DPM mode or thermal regulation.
When a fully charged battery is discharged below recharge threshold (selectable through VRECHG bit), the
device automatically starts a new charging cycle. After the charge is done, toggle CE pin or CHG_CONFIG bit
can initiate a new charging cycle.
The STAT output indicates the charging status: charging (LOW), charging complete or charge disable (HIGH) or
charging fault (Blinking). The STAT output can be disabled by setting EN_ICHG_MON bits = 11. in addition, the
status register (CHRG_STAT) indicates the different charging phases: 00-charging disable, 01-precharge, 10-fast
charge (constant current) and constant voltage mode, 11-charging done. Once a charging cycle is completed, an
INT is asserted to notify the host.
8.3.7.2 Battery Charging Profile
The device charges the battery in five phases: battery short, preconditioning, constant current, constant voltage
and top-off trickle charging (optional). At the beginning of a charging cycle, the device checks the battery voltage
and regulates current and voltage accordingly.
Table 3. Charging Current Setting
VBAT

CHARGinG CURRENT

REGISTER DEFAULT
SETTinG

CHRG_STAT

& lt; 2.2 V

ISHORT

100 mA

01

2.2 V to 3 V

IPRECHG

180 mA

01

& gt; 3V

ICHG

2.048 A

10

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

19

bq25601
SLUSCK5 – MARCH 2017

www.ti.com

If the charger device is in DPM regulation or thermal regulation during charging, the actual charging current will
be less than the programmed value. in this case, termination is temporarily disabled and the charging safety
timer is counted at half the clock rate.
Regulation Voltage
VREG[7:3]
Battery Voltage
Charge Current
ICHG[5:0]
Charge Current

VBATLOWV (3 V)

VSHORTZ (2.2 V)

IPRECHG[7:4]
ITERM[3:0]
ISHORT
Trickle Charge

Pre-charge

Fast Charge and Voltage Regulation

Top-off Timer
(optional)

Safety Timer
Expiration

Figure 11. Battery Charging Profile
8.3.7.3 Charging Termination
The device terminates a charge cycle when the battery voltage is above recharge threshold, and the current is
below termination current. After the charging cycle is completed, the BATFET turns off. The converter keeps
running to power the system, and BATFET can turn on again to engage Supplement Mode.
When termination occurs, the status register CHRG_STAT is set to 11, and an INT pulse is asserted to the host.
Termination is temporarily disabled when the charger device is in input current, voltage or thermal regulation.
Termination can be disabled by writing 0 to EN_TERM bit prior to charge termination.
At low termination currents (25 mA-50 mA), due to the comparator offset, the actual termination current may be
10 mA-20 mA higher than the termination target. in order to compensate for comparator offset, a programmable
top-off timer can be applied after termination is detected. The termination timer will follow safety timer
constraints, such that if safety timer is suspended, so will the termination timer. Similarly, if safety timer is
doubled, so will the termination timer. TOPOFF_ACTIVE bit reports whether the top off timer is active or not. The
host can read CHRG_STAT and TOPOFF_ACTIVE to find out the termination status.
Top off timer gets reset at one of the following conditions:
1. Charge disable to enable
2. Termination status low to high
3. REG_RST register bit is set
The top-off timer settings are read in once termination is detected by the charger. Programming a top-off timer
value after termination will have no effect unless a recharge cycle is initiated. An INT is asserted to the host
when entering top-off timer segment as well as when top-off timer expires.
8.3.7.4 Thermistor Qualification
The charger device provides a single thermistor input for battery temperature monitor.

20

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

bq25601
www.ti.com

SLUSCK5 – MARCH 2017

8.3.7.5 JEITA Guideline Compliance During Charging Mode
To improve the safety of charging Li-ion batteries, JEITA guideline was released on April 20, 2007. The guideline
emphasized the importance of avoiding a high charge current and high charge voltage at certain low and high
temperature ranges.
To initiate a charge cycle, the voltage on TS pin must be within the VT1 to VT5 thresholds. If TS voltage exceeds
the T1-T5 range, the controller suspends charging and waits until the battery temperature is within the T1 to T5
range.
At cool temperature (T1-T2), JEITA recommends the charge current to be reduced to half of the charge current
or lower. At warm temperature (T3-T5), JEITA recommends charge voltage less than 4.1 V.
The charger provides flexible voltage/current settings beyond the JEITA requirement. The voltage setting at
warm temperature (T3-T5) can be VREG or 4.1V (configured by JEITA_VSET). The current setting at cool
temperature (T1-T2) can be further reduced to 20% of fast charge current (JEITA_ISET).
100

VREG

90

Charging Voltage (V)

Charging Current (%)

80
70
60
50

ISET = 0

40
30
20

VSET = 0

4.1

VSET = 1

ISET = 1

10
0

0
T2

T1

±5

0

5

T3

10 15 20 25 30

35 40 45 50

T1

T5
55 60 65

70

±5

0

T2
5

T3

10 15 20 25 30

Junction Temperature (°
C)

35 40 45 50

T5
55 60 65

70

Junction Temperature (°
C)

Figure 12. JEITA Profile: Charging Current
Figure 13. JEITA Profile: Charging Voltage
Equation 1 through Equation 2 describe updates to the resistor bias network.
1 ö
æ 1
VREGN ´ RTHCOLD ´ RTHHOT ´ ç
VT1 VT5 ÷
è
ø
RT2 =
æ VREGN
ö
æ VREGN
ö
RTHHOT ´ ç
- 1÷ - RTHCOLD ´ ç
- 1÷
VT5
VT1
è
ø
è
ø

æ æ VREGN ö
ö
çç
÷ - 1÷
è è VT1 ø
ø
RT1 =
æ
ö
1
æ 1 ö
÷
ç RT2 ÷ + ç RTH
è
ø è
COLD ø

(1)

(2)

Select 0°C to 60°C range for Li-ion or Li-polymer battery:
• RTHCOLD = 27.28 KΩ
• RTHHOT = 3.02 KΩ
• RT1 = 5.23 KΩ
• RT2 = 30.9 KΩ
8.3.7.6 Boost Mode Thermistor Monitor during Battery Discharge Mode
For battery protection during boost mode, the device monitors the battery temperature to be within the to
thresholds. When temperature is outside of the temperature thresholds, the boost mode is suspended. In
additional, VBUS_STAT bits are set to 000 and NTC_FAULT is reported. Once temperature returns within
thresholds, the boost mode is recovered and NTC_FAULT is cleared.
Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

21

bq25601
SLUSCK5 – MARCH 2017

www.ti.com

Temperature Range to Boost
VREGN
Boost Disabled
VBCOLD
(±10°
C)

Boost Enabled
VBHOT
(65°
C)

Boost Disabled
AGND

Figure 14. TS Pin Thermistor Sense Threshold in Boost Mode
8.3.7.7 Charging Safety Timer
The device has built-in safety timer to prevent extended charging cycle due to abnormal battery conditions. The
safety timer is 2 hours when the battery is below VBATLOWV threshold and 10 hours when the battery is higher
than VBATLOWV threshold.
The user can program fast charge safety timer through I2C (CHG_TIMER bits). When safety timer expires, the
fault register CHRG_FAULT bits are set to 11 and an INT is asserted to the host. The safety timer feature can be
disabled through I2C by setting EN_TIMER bit
During input voltage, current, JEITA cool or thermal regulation, the safety timer counts at half clock rate as the
actual charge current is likely to be below the register setting. For example, if the charger is in input current
regulation (IDPM_STAT = 1) throughout the whole charging cycle, and the safety time is set to 5 hours, the
safety timer will expire in 10 hours. This half clock rate feature can be disabled by writing 0 to TMR2X_EN bit.
During the fault, timer is suspended. Once the fault goes away, fault resumes. If user stops the current charging
cycle, and start again, timer gets reset (toggle CE pin or CHRG_CONFIG bit).
8.3.7.8 Narrow VDC Architecture
The device deploys Narrow VDC architecture (NVDC) with BATFET separating system from battery. The
minimum system voltage is set by SYS_Min bits. Even with a fully depleted battery, the system is regulated
above the minimum system voltage.
When the battery is below minimum system voltage setting, the BATFET operates in linear mode (LDO mode),
and the system is typically 180 mV above the minimum system voltage setting. As the battery voltage rises
above the minimum system voltage, BATFET is fully on and the voltage difference between the system and
battery is the VDS of BATFET.
When the battery charging is disabled and above minimum system voltage setting or charging is terminated, the
system is always regulated at typically 50mV above battery voltage. The status register VSYS_STAT bit goes
high when the system is in minimum system voltage regulation.

22

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

bq25601
www.ti.com

SLUSCK5 – MARCH 2017

4.5
Charge Disabled
Charge Enabled
Minimum System Voltage

4.3

SYS (V)

4.1
3.9
3.7
3.5
3.3
3.1
2.7

2.9

3.1

3.3

3.5
3.7
BAT (V)

3.9

4.1

4.3
D002

Plot1

Figure 15. System Voltage vs Battery Voltage
8.3.7.9 Dynamic Power management
To meet maximum current limit in USB spec and avoid over loading the adapter, the device features Dynamic
Power management (DPM), which continuously monitors the input current and input voltage. When input source
is over-loaded, either the current exceeds the input current limit (IIDPM) or the voltage falls below the input
voltage limit (VINDPM). The device then reduces the charge current until the input current falls below the input
current limit and the input voltage rises above the input voltage limit.
When the charge current is reduced to zero, but the input source is still overloaded, the system voltage starts to
drop. Once the system voltage falls below the battery voltage, the device automatically enters the supplement
mode where the BATFET turns on and battery starts discharging so that the system is supported from both the
input source and battery.
During DPM mode, the status register bits VDPM_STAT (VINDPM) or IDPM_STAT (IINDPM) goes high.
Figure 16 shows the DPM response with 9-V/1.2-A adapter, 3.2-V battery, 2.8-A charge current and 3.5-V
minimum system voltage setting.
Voltage
VBUS
9V

SYS

3.6V
3.4V
3.2V
3.18V

BAT

Current
4A
ICHG

3.2A
2.8A

ISYS

1.2A
1.0A
0.5A

IIN

-0.6A
DPM

DPM
Supplement

Figure 16. DPM Response

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

23

bq25601
SLUSCK5 – MARCH 2017

www.ti.com

8.3.7.10 Supplement Mode
When the system voltage falls 180 mV (VBAT & gt; VSYSMin) or 45 mV (VBAT & lt; VSYSMin) below the battery
voltage, the BATFET turns on and the BATFET gate is regulated the gate drive of BATFET so that the minimum
BATFET VDS stays at 30 mV when the current is low. This prevents oscillation from entering and exiting the
supplement mode.
As the discharge current increases, the BATFET gate is regulated with a higher voltage to reduce RDSON until
the BATFET is in full conduction. At this point onwards, the BATFET VDS linearly increases with discharge
current. Figure 17 shows the V-I curve of the BATFET gate regulation operation. BATFET turns off to exit
supplement mode when the battery is below battery depletion threshold.
4.5
4
3.5
Current (A)

3
2.5
2
1.5
1
0.5
0
0

5

10

15

20 25 30 35
V(BAT-SYS) (mV)

40

45

50

55
D001

Plot1

Figure 17. BAFET V-I Curve
8.3.8 Shipping Mode and QON Pin
8.3.8.1 BATFET Disable Mode (Shipping Mode)
To extend battery life and minimize power when system is powered off during system idle, shipping, or storage,
the device can turn off BATFET so that the system voltage is zero to minimize the battery leakage current. When
the host set BATFET_DIS bit, the charger can turn off BATFET immediately or delay by tSM_DLY as configured by
BATFET_DLY bit.
8.3.8.2 BATFET Enable (Exit Shipping Mode)
When the BATFET is disabled (in shipping mode) and indicated by setting BATFET_DIS, one of the following
events can enable BATFET to restore system power:
1. Plug in adapter
2. Clear BATFET_DIS bit
3. Set REG_RST bit to reset all registers including BATFET_DIS bit to default (0)
4. A logic high to low transition on QON pin with tSHIPMODE deglitch time to enable BATFET to exit shipping
mode
8.3.8.3 BATFET Full System Reset
The BATFET functions as a load switch between battery and system when input source is not pluggeD–in. By
changing the state of BATFET from on to off, systems connected to SYS can be effectively forced to have a
power-on-reset. The QON pin supports push-button interface to reset system power without host by changing the
state of BATFET.
When the QON pin is driven to logic low for tQON_RST while input source is not plugged in and BATFET is enabled
(BATFET_DIS = 0), the BATFET is turned off for tBATFET_RST and then it is re-enabled to reset system power. This
function can be disabled by setting BATFET_RST_EN bit to 0.

24

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

bq25601
www.ti.com

SLUSCK5 – MARCH 2017

8.3.8.4 QON Pin Operations
The QON pin incorporates two functions to control BATFET.
1. BATFET Enable: A QON logic transition from high to low with longer than tSHIPMODE deglitch turns on
BATFET and exit shipping mode
2. BATFET Reset: When QON is driven to logic low by at least tQON_RST while adapter is not plugged in (and
BATFET_DIS = 0), the BATFET is turned off for tBATFET_RST. The BATFET is re-enabled after tBATFET_RST
duration. This function allows systems connected to SYS to have power-on-reset. This function can be
disabled by setting BATFET_RST_EN bit to 0.
Figure 18 shows the sample external configurations for each.
QON
Press
push button

Press
push button
tQON_RST

tSHIPMODE

tBATFET_RST

Q4 Status

2

Q4 off due to I C or
system overload

Q4
off

Q4 on

Turn on Q4 FET
when BATFET_DIS = 1 or SLEEPZ = 1

Q4 on

Reset Q4 FET
When BATFET_DIS = 0 and SLEEPZ = 0

Figure 18. QON Timing
SYS

Q4
Control
BAT
VPULL-UP

+

QON

Figure 19. QON Circuit
8.3.9 Status Outputs (PG, STAT, INT)
8.3.9.1 Power Good indicator (PG Pin and PG_STAT Bit)
The PG_STAT bit goes HIGH and PG pin goes LOW to indicate a good input source when:
• VBUS above VVBUS_UVLO
• VBUS above battery (not in sleep)
• VBUS below VVAC_OV threshold
• VBUS above VVBUSMin (typical 3.8 V) when IBADSRC (typical 30 mA) current is applied (not a poor source)
• Completed input Source Type Detection
8.3.9.2 Charging Status indicator (STAT)
The device indicates charging state on the open drain STAT pin. The STAT pin can drive LED. The STAT pin
function can be disabled by setting the EN_ICHG_MON bits = 11.
Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

25

bq25601
SLUSCK5 – MARCH 2017

www.ti.com

Table 4. STAT Pin State
CHARGING STATE

STAT INDICATOR

Charging in progress (including recharge)

LOW

Charging complete

HIGH

Sleep mode, charge disable

HIGH

Charge suspend (input overvoltage, TS fault, timer fault or system overvoltage)
Boost Mode suspend (due to TS fault)

Blinking at 1 Hz

8.3.9.3 Interrupt to Host (INT)
In some applications, the host does not always monitor the charger operation. The INT pulse notifies the system
on the device operation. The following events will generate 256-μs INT pulse.
• USB/adapter source identified (through PSEL detection)
• Good input source detected
– VBUS above battery (not in sleep)
– VBUS below VVAC_OV threshold
– VBUS above VVBUSMin (typical 3.8 V) when IBADSRC (typical 30 mA) current is applied (not a poor source)
• input removed
• Charge Complete
• Any FAULT event in REG09
• VINDPM / IINDPM event detected (maskable)
When a fault occurs, the charger device sends out INT and keeps the fault state in REG09 until the host reads
the fault register. Before the host reads REG09 and all the faults are cleared, the charger device would not send
any INT upon new faults. To read the current fault status, the host has to read REG09 two times consecutively.
The first read reports the pre-existing fault register status and the second read reports the current fault register
status.
8.3.10 Protections
8.3.10.1 Voltage and Current Monitoring in Converter Operation
The device closely monitors the input and system voltage, as well as internal FET currents for safe buck and
boost mode operation.
8.3.10.1.1 Voltage and Current Monitoring in Buck Mode
8.3.10.1.1.1 Input Overvoltage (ACOV)

If VBUS voltage exceeds VVAC_OV (programmable via OVP[2:0] bits), the device stops switching immediately.
During input overvoltage event (ACOV), the fault register CHRG_FAULT bits are set to 01. An INT pulse is
asserted to the host. The device will automatically resume normal operation once the input voltage drops back
below the OVP threshold.
8.3.10.1.1.2 System Overvoltage Protection (SYSOVP)

The charger device clamps the system voltage during load transient so that the components connect to system
would not be damaged due to high voltage. SYSOVP threshold is 350 mV above minimum system regulation
voltage when the system is regulate at VSYSMIN. Upon SYSOVP, converter stops switching immediately to clamp
the overshoot. The charger provides 30 mA discharge current to bring down the system voltage.
8.3.10.2 Voltage and Current Monitoring in Boost Mode
The device closely monitors the VBUS voltage, as well as RBFET and LSFET current to ensure safe boost mode
operation.
8.3.10.2.1 VBUS Soft Start

When the boost function is enabled, the device soft-starts boost mode to avoid inrush current.
26

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

bq25601
www.ti.com

SLUSCK5 – MARCH 2017

8.3.10.2.2 VBUS Output Protection

The device monitors boost output voltage and other conditions to provide output short circuit and overvoltage
protection. The Boost build in accurate constant current regulation to allow OTG to adaptive to various types of
load. If short circuit is detected on VBUS, the Boost turns off and retry 7 times. If retries are not successful, OTG
is disabled with OTG_CONFIG bit cleared. In addition, the BOOST_FAULT bit is set and INT pulse is generated.
The BOOST_FAULT bit can be cleared by host by re-enabling boost mode
8.3.10.2.3 Boost Mode Overvoltage Protection

When the VBUS voltage rises above regulation target and exceeds VOTG_OVP, the device enters overvoltage
protection which stops switching, clears OTG_CONFIG bit and exits boost mode. At Boost overvoltage duration,
the fault register bit (BOOST_FAULT) is set high to indicate fault in boost operation. An INT is also asserted to
the host.
8.3.10.3 Thermal Regulation and Thermal Shutdown
8.3.10.3.1 Thermal Protection in Buck Mode

The bq25601 monitors the internal junction temperature TJ to avoid overheat the chip and limits the IC surface
temperature in buck mode. When the internal junction temperature exceeds thermal regulation limit (110°C), the
device lowers down the charge current. During thermal regulation, the actual charging current is usually below
the programmed battery charging current. Therefore, termination is disabled, the safety timer runs at half the
clock rate, and the status register THERM_STAT bit goes high.
Additionally, the device has thermal shutdown to turn off the converter and BATFET when IC surface
temperature exceeds TSHUT(160ºC). The fault register CHRG_FAULT is set to 1 and an INT is asserted to the
host. The BATFET and converter is enabled to recover when IC temperature is TSHUT_HYS (30ºC) below
TSHUT(160ºC).
8.3.10.3.2 Thermal Protection in Boost Mode

The device monitors the internal junction temperature to provide thermal shutdown during boost mode. When IC
junction temperature exceeds TSHUT (160ºC), the boost mode is disabled by setting OTG_CONFIG bit low and
BATFET is turned off. When IC junction temperature is below TSHUT(160ºC) - TSHUT_HYS (30ºC), the BATFET is
enabled automatically to allow system to restore and the host can re-enable OTG_CONFIG bit to recover.
8.3.10.4 Battery Protection
8.3.10.4.1 Battery overvoltage Protection (BATOVP)

The battery overvoltage limit is clamped at 4% above the battery regulation voltage. When battery over voltage
occurs, the charger device immediately disables charging. The fault register BAT_FAULT bit goes high and an
INT is asserted to the host.
8.3.10.4.2 Battery Over-Discharge Protection

When battery is discharged below VBAT_DPL_FALL, the BATFET is turned off to protect battery from over discharge.
To recover from over-discharge latch-off, an input source plug-in is required at VBUS. The battery is charged
with ISHORT (typically 100 mA) current when the VBAT & lt; VSHORT, or precharge current as set in IPRECHG
register when the battery voltage is between VSHORTZ and VBAT_LOWV.
8.3.10.4.3 System Over-Current Protection

When the system is shorted or significantly overloaded (IBAT & gt; IBATOP) and the current exceeds BATFET
overcurrent limit, the BATFET latches off. Section BATFET Enable (Exit Shipping Mode) can reset the latch-off
condition and turn on BATFET.

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

27

bq25601
SLUSCK5 – MARCH 2017

www.ti.com

8.3.11 Serial interface
The device uses I2C compatible interface for flexible charging parameter programming and instantaneous device
status reporting. I2CTM is a bi-directional 2-wire serial interface developed by Philips Semiconductor (now NXP
Semiconductors). Only two bus lines are required: a serial data line (SDA) and a serial clock line (SCL). Devices
can be considered as masters or slaves when performing data transfers. A master is the device which initiates a
data transfer on the bus and generates the clock signals to permit that transfer. At that time, any device
addressed is considered a slave.
The device operates as a slave device with address 6BH, receiving control inputs from the master device like
micro controller or a digital signal processor through REG00-REG0B. Register read beyond REG0B (0x0B)
returns 0xFF. The I2C interface supports both standard mode (up to 100 kbits), and fast mode (up to 400 kbits).
connecting to the positive supply voltage via a current source or pull-up resistor. When the bus is free, both lines
are HIGH. The SDA and SCL pins are open drain.
8.3.11.1 Data Validity
The data on the SDA line must be stable during the HIGH period of the clock. The HIGH or LOW state of the
data line can only change when the clock signal on the SCL line is LOW. One clock pulse is generated for each
data bit transferred.

SDA

SCL

Data line stable;
Data valid

Change of data
allowed

Figure 20. Bit Transfer on the I2C Bus
8.3.11.2 START and STOP Conditions
All transactions begin with a START (S) and can be terminated by a STOP (P). A HIGH to LOW transition on the
SDA line while SCl is HIGH defines a START condition. A LOW to HIGH transition on the SDA line when the
SCL is HIGH defines a STOP condition. START and STOP conditions are always generated by the mAster. The
bus is considered busy after the START condition, and free after the STOP condition.

SDA

SDA

SCL

SCL
START (S)

STOP (P)

Figure 21. TS START and STOP conditions
8.3.11.3 Byte Format
Every byte on the SDA line must be 8 bits long. The number of bytes to be transmitted per transfer is
unrestricted. Each byte has to be followed by an Acknowledge bit. Data is transferred with the Most Significant
Bit (MSB) first. If a slave cannot receive or transmit another complete byte of data until it has performed some
other function, it can hold the clock line SCL low to force the mAster into a wait state (clock stretching). Data
transfer then continues when the slave is ready for another byte of data and release the clock line SCL.

28

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

bq25601
www.ti.com

SLUSCK5 – MARCH 2017

Acknowledgement
signal from slave
MSB

SDA

SCL

Acknowledgement
signal from receiver

1

S or Sr

2

7

8

9

START or
Repeated
START

1

2

8

9

P or Sr
STOP or
Repeated
START

ACK

ACK

Figure 22. Data Transfer on the I2C Bus
8.3.11.4 Acknowledge (ACK) and Not Acknowledge (NACK)
The acknowledge takes place after every byte. The acknowledge bit allows the receiver to signal the transmitter
that the byte was successfully received and another byte may be sent. All clock pulses, including the
acknowledge ninth clock pulse, are generated by the mAster. The transmitter releases the SDA line during the
acknowledge clock pulse so the receiver can pull the SDA line LOW and it remains stable LOW during the HIGH
period of this clock pulse.
When SDA remains HIGH during the ninth clock pulse, this is the Not Acknowledge signal. The mAster can then
generate either a STOP to abort the transfer or a repeated START to start a new transfer.
8.3.11.5 Slave Address and Data Direction Bit
After the START, a slave address is sent. This address is 7 bits long followed by the eighth bit as a data direction
bit (bit R/W). A zero indicates a transmission (WRITE) and a one indicates a request for data (READ).

SDA

SCL

1-7

8

9

ADDRESS

R/W

ACK

S
START

1-7

8

9

DATA

1-7

ACK

8

DATA

9
ACK

P
STOP

Figure 23. Complete Data Transfer
8.3.11.6 Single Read and Write
If the register address is not defined, the charger IC send back NACK and go back to the idle state.
1

7

1

1

8

1

8

1

1

S

Slave Address

0

ACK

Reg Addr

ACK

Data to Addr

ACK

P

Figure 24. Single Write
1

7

1

1

8

1

1

7

1

1

S

Slave Address

0

ACK

Reg Addr

ACK

S

Slave Addr

1

ACK

8

1

1

Data

NCK

P

Figure 25. Single Read
8.3.11.7 Multi-Read and Multi-Write
The charger device supports multi-read and multi-write on REG00 through REG0B.

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

29

bq25601
SLUSCK5 – MARCH 2017

www.ti.com

1

7

1

1

8

1

S

Slave Address

0

ACK

Reg Addr

ACK

8

1

8

1

8

1

1

Data to Addr

ACK

Data to Addr + N

ACK

Data to Addr + N

ACK

P

Figure 26. Multi-Write
1

7

1

1

8

1

1

7

1

1

S

Slave Address

0

ACK

Reg Addr

ACK

S

Slave Address

1

ACK

8

1

8

1

8

1

1

Data @ Addr

ACK

Data @ Addr + 1

ACK

Data @ Addr + N

NCK

P

Figure 27. Multi-Read
REG09 is a fault register. It keeps all the fault information from last read until the host issues a new read. For
example, if Charge Safety Timer Expiration fault occurs but recovers later, the fault register REG09 reports the
fault when it is read the first time, but returns to normal when it is read the second time. in order to get the fault
information at present, the host has to read REG09 for the second time. The only exception is NTC_FAULT
which always reports the actual condition on the TS pin. in addition, REG09 does not support multi-read and
multi-write.

30

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

bq25601
www.ti.com

SLUSCK5 – MARCH 2017

8.4 Register Maps
I2C Slave Address: 6BH
8.4.1 REG00
Table 5. REG00 Field Descriptions
Bit

Field

POR

Type

Reset

EN_HIZ

0

R/W

by REG_RST
0 – Disable, 1 – Enable
by Watchdog

6

EN_ICHG_MON[1]

0

R/W

5

EN_ICHG_MON[0]

0

R/W

4

IINDPM[4]

1

R/W

by REG_RST 1600 mA

3

IINDPM[3]

0

R/W

by REG_RST 800 mA

2

IINDPM[2]

1

R/W

by REG_RST 400 mA

1

IINDPM[1]

1

R/W

by REG_RST 200 mA

0

IINDPM[0]

1

R/W

by REG_RST 100 mA

7

Description

Comment
Enable HIZ Mode
0 – Disable (default)
1 – Enable

by REG_RST 00 - Enable STAT pin function
(default)
01 - Reserved
by REG_RST 10 - Reserved
11 - Disable STAT pin function
(float pin)
Input Current Limit
Offset: 100 mA
Range: 100 mA (000000) – 3.2 A
(11111)
Default:2400 mA (10111),
maximum input current limit, not
typical.
IINDPM bits are changed
automatically after input source
detection is completed
PSEL = Hi = 500 mA
PSEL = Lo = 2.4 A
Host can over-write IINDPM
register bits after input source
detection is completed.

LEGEND: R/W = Read/Write; R = Read only

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

31

bq25601
SLUSCK5 – MARCH 2017

www.ti.com

8.4.2 REG01
Table 6. REG01 Field Descriptions
Bit

Field

POR

Type

Reset

Description

Comment

0 – Enable PFM
1 – Disable PFM

Default: 0 - Enable

7

PFM _DIS

0

R/W

by REG_RST

6

WD_RST

0

R/W

by REG_RST I2C Watchdog Timer Reset 0 –
by Watchdog Normal ; 1 – Reset

Default: Normal (0) Back to 0 after
watchdog timer reset

R/W

by REG_RST 0 – OTG Disable
by Watchdog 1 – OTG Enable

Default: OTG disable (0)
Note:
1. OTG_CONFIG would over-ride
Charge Enable Function in
CHG_CONFIG
Default: Charge Battery (1)
Note:
1. Charge is enabled when both
CE pin is pulled low AND
CHG_CONFIG bit is 1.

5

OTG_CONFIG

0

4

CHG_CONFIG

1

R/W

by REG_RST 0 - Charge Disable
by Watchdog 1- Charge Enable

3

SYS_Min[2]

1

R/W

by REG_RST

2

SYS_Min[1]

0

R/W

by REG_RST

1

SYS_Min[0]

1

R/W

by REG_RST

0

Min_VBAT_SEL

0

R/W

by REG_RST

System Minimum Voltage

000: 2.6 V
001: 2.8 V
010: 3 V
011: 3.2 V
100: 3.4 V
101: 3.5 V
110: 3.6 V
111: 3.7 V
Default: 3.5 V (101)

0 – 2.8 V BAT falling,
1 – 2.5 V BAT falling

Minimum battery voltage for OTG
mode. Default falling 2.8 V (0);
Rising threshold 3.0 V (0)

LEGEND: R/W = Read/Write; R = Read only

32

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

bq25601
www.ti.com

SLUSCK5 – MARCH 2017

8.4.3 REG02
Table 7. REG02 Field Descriptions
Bit
7

Field
BOOST_LIM

POR

Type

1

R/W

Reset

Description

Comment

by REG_RST
by Watchdog 0 = 0.5 A
1 = 1.2 A

Default: 1.2 A (1)
Note:
The current limit options listed are
minimum current limit specs.

6

Q1_FULLON

0

R/W

by REG_RST 0 – Use higher Q1 RDSON when
programmed IINDPM & lt; 700mA
(better accuracy)
1 – Use lower Q1 RDSON always
(better efficiency)

5

ICHG[5]

1

R/W

by REG_RST
1920 mA
by Watchdog

4

ICHG[4]

0

R/W

by REG_RST
960 mA
by Watchdog

3

ICHG[3]

0

R/W

by REG_RST
480 mA
by Watchdog

2

ICHG[2]

0

R/W

by REG_RST
240 mA
by Watchdog

1

ICHG[1]

1

R/W

by REG_RST
120 mA
by Watchdog

0

ICHG[0]

0

R/W

by REG_RST
60 mA
by Watchdog

In boost mode, full FET is always
used and this bit has no effect

Fast Charge Current
Default: 2040mA (100010)
Range: 0 mA (0000000) – 3000
mA (110010)
Note:
ICHG = 0 mA disables charge.
ICHG & gt; 3000 mA (110010 clamped
to register value 3000 mA
(110010))

LEGEND: R/W = Read/Write; R = Read only

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

33

bq25601
SLUSCK5 – MARCH 2017

www.ti.com

8.4.4 REG03
Table 8. REG03 Field Descriptions
Bit

Field

POR

Type

Reset

Description

7

IPRECHG[3]

0

R/W

by REG_RST
480 mA
by Watchdog

6

IPRECHG[2]

0

R/W

by REG_RST
240 mA
by Watchdog

5

IPRECHG[1]

1

R/W

by REG_RST
120 mA
by Watchdog

4

IPRECHG[0]

0

R/W

by REG_RST
60 mA
by Watchdog

3

ITERM[3]

0

R/W

by REG_RST
480 mA
by Watchdog

2

ITERM[2]

0

R/W

by REG_RST
240 mA
by Watchdog

1

ITERM[1]

1

R/W

by REG_RST
120 mA
by Watchdog

0

ITERM[0]

0

R/W

Comment

by REG_RST
60 mA
by Watchdog

Precharge Current
Default: 180 mA (0010)
Offset: 60 mA
Note: IPRECHG & gt; 780 mA
clamped to 780 mA (1100)

Termination Current
Default: 180 mA (0010)
Offset: 60 mA

LEGEND: R/W = Read/Write; R = Read only

34

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

bq25601
www.ti.com

SLUSCK5 – MARCH 2017

8.4.5 REG04
Table 9. REG04 Field Descriptions
Bit

Field

POR

Type

Reset

Description

Comment

7

VREG[4]

0

R/W

by REG_RST
512 mV
by Watchdog

6

VREG[3]

1

R/W

by REG_RST
256 mV
by Watchdog

5

VREG[2]

0

R/W

by REG_RST
128 mV
by Watchdog

4

VREG[1]

1

R/W

by REG_RST
64 mV
by Watchdog

3

VREG[0]

1

R/W

by REG_RST
32 mV
by Watchdog

(01111): 4.352 V
Note: Value above 11000 (4.624
V) is clamped to register value
11000 (4.624 V)

2

TOPOFF_TIMER[1]

0

R/W

1

TOPOFF_TIMER[0]

0

R/W

by REG_RST 00 –
by Watchdog 01 –
by REG_RST 10 –
by Watchdog 11 –

The extended time following the
termination condition is met. When
disabled, charge terminated when
termination conditions are met

0

VRECHG

0

R/W

Disabled (Default)
15 minutes
30 minutes
45 minutes

by REG_RST 0 – 100 mV
by Watchdog 1 – 200 mV

Charge Voltage
Offset: 3.856 V
Range: 3.856
(11000)

V

to

4.624

V

Default: 4.208 V (01011)
Special Value:

Recharge threshold
Default: 100mV (0)

LEGEND: R/W = Read/Write; R = Read only

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

35

bq25601
SLUSCK5 – MARCH 2017

www.ti.com

8.4.6 REG05
Table 10. REG05 Field Descriptions
Bit

Field

POR

Type

Reset

Description

Comment

7

EN_TERM

1

R/W

by REG_RST 0 – Disable
by Watchdog 1 – Enable

Default: Enable termination (1)

6

Reserved

0

R/W

by REG_RST
Reserved
by Watchdog

Reserved

5

WATCHDOG[1]

0

R/W

4

WATCHDOG[0]

1

R/W

3

EN_TIMER

1

R/W

0 – Disable
by REG_RST
1 – Enable both fast charge and
by Watchdog
precharge timer

Default: Enable (1)

2

CHG_TIMER

1

R/W

by REG_RST 0 – 5 hrs
by Watchdog 1 – 10 hrs

Default: 10 hours (1)

1

TREG

1

R/W

Thermal Regulation Threshold:
by REG_RST
0 - 90°C
by Watchdog
1 - 110°C

Default: 110°C (1)

0

JEITA_ISET
(0C-10C)

1

R/W

by REG_RST 0 – 50% of ICHG
by Watchdog 1 – 20% of ICHG

Default: 20% (1)

by REG_RST
by Watchdog 00 – Disable timer, 01 – 40 s, 10 –
Default: 40 s (01)
by REG_RST 80 s,11 – 160 s
by Watchdog

LEGEND: R/W = Read/Write; R = Read only

36

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

bq25601
www.ti.com

SLUSCK5 – MARCH 2017

8.4.7 REG06
Table 11. REG06 Field Descriptions
Bit

Field

POR

Type

Reset

Description

Comment

Default: 6.5V (01)

VAC OVP threshold:
00 - 5.5 V
01 – 6.5 V (5-V input)
10 – 10.5 V (9-V input)
11 – 14 V (12-V input)

7

OVP[1]

0

R/W

by REG_RST

6

OVP[0]

1

R/W

by REG_RST

5

BOOSTV[1]

1

R/W

by REG_RST

4

BOOSTV[0]

0

R/W

by REG_RST

3

VINDPM[3]

0

R/W

by REG_RST 800 mV

2

VINDPM[2]

1

R/W

by REG_RST 400 mV

1

VINDPM[1]

1

R/W

by REG_RST 200 mV

0

VINDPM[0]

0

R/W

by REG_RST 100 mV

Boost Regulation Voltage:
00 - 4.85V
01 - 5.00V
10 - 5.15V
11 - 5.30V
Absolute VINDPM Threshold
Offset: 3.9 V
Range: 3.9 V (0000) – 5.4 V
(1111)
Default: 4.5V (0110)

LEGEND: R/W = Read/Write; R = Read only

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

37

bq25601
SLUSCK5 – MARCH 2017

www.ti.com

8.4.8 REG07
Table 12. REG07 Field Descriptions
Bit

Field

POR

Type

Reset

Description

Comment

7

IINDET_EN

0

R/W

0 - Not in input current limit
by REG_RST detection
by Watchdog 1 - Force input current limit
detection when VBUS is present

6

TMR2X_EN

1

R/W

0 – Disable
by REG_RST 1 – Safety timer slowed by 2X
by Watchdog during input DPM (both V and I) or
JEITA cool, or thermal regulation

5

BATFET_DIS

0

R/W

0 – Allow Q4 turn on, 1 – Turn off
by REG_RST Q4 with tBATFET_DLY delay time
(REG07[3])

4

JEITA_VSET
(45C-60C)

0

R/W

by REG_RST 0 – Set Charge Voltage to 4.1V (
max),
by Watchdog 1 – Set Charge Voltage to VREG

Returns to 0 after input detection
is complete

Default: Allow Q4 turn on(0)

3

BATFET_DLY

1

R/W

0 – Turn off BATFET immediately
when BATFET_DIS bit is set
by REG_RST 1 –Turn off BATFET after
tBATFET_DLY (typ. 10 s) when
BATFET_DIS bit is set

2

BATFET_RST_EN

1

R/W

by REG_RST 0 – Disable BATFET reset function Default: 1
by Watchdog 1 – Enable BATFET reset function Enable BATFET reset function

1

VDPM_BAT_TRACK[1]

0

R/W

0

VDPM_BAT_TRACK[0]

0

R/W

by REG_RST 00 - Disable function (VINDPM set
by register)
01 - VBAT + 200mV
by REG_RST 10 - VBAT + 250mV
11 - VBAT + 300mV

Default: 1
Turn off BATFET after tBATFET_DLY
(typ. 10 s) when BATFET_DIS bit
is set

Sets VINDPM to track BAT
voltage. Actual VINDPM is higher
of register value and VBAT +
VDPM_BAT_TRACK

LEGEND: R/W = Read/Write; R = Read only

38

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

bq25601
www.ti.com

SLUSCK5 – MARCH 2017

8.4.9 REG08
Table 13. REG08 Field Descriptions
Bit

Field

POR

Type

Reset

Description
VBUS Status register
000: No input
001: USB Host SDP (500 mA) → PSEL HIGH
010: Adapter 2.4A → PSEL LOW
111: OTG
Software current limit is reported in IINDPM register

7

VBUS_STAT[2]

x

R

NA

6

VBUS_STAT[1]

x

R

NA

5

VBUS_STAT[0]

x

R

NA

4

CHRG_STAT[1]

x

R

NA

3

CHRG_STAT[0]

x

R

NA

2

PG_STAT

x

R

NA

Power Good status:
0 – Power Not Good
1 – Power Good

1

THERM_STAT

x

R

NA

0 – Not in ther mAl regulation
1 – in ther mAl regulation

0

VSYS_STAT

x

R

NA

0 – Not in VSYSMin regulation (BAT & gt; VSYSMin)
1 – in VSYSMin regulation (BAT & lt; VSYSMin)

Charging status:
00 – Not Charging
01 – Pre-charge ( & lt; VBATLOWV)
10 – Fast Charging
11 – Charge Termination

LEGEND: R/W = Read/Write

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

39

bq25601
SLUSCK5 – MARCH 2017

www.ti.com

8.4.10 REG09
Table 14. REG09 Field Descriptions
Bit

Field

POR

Type

Reset

Description

7

WATCHDOG_FAULT

x

R

NA

0 – Normal, 1- Watchdog timer expiration

6

BOOST_FAULT

x

R

NA

0 – Normal, 1 – VBUS overloaded in OTG, or VBUS OVP, or battery is
too low (any conditions that we cannot start boost function)

5

CHRG_FAULT[1]

x

R

NA

4

CHRG_FAULT[0]

x

R

NA

00 – Normal, 01 – input fault (VAC OVP or VBAT & lt; VBUS & lt; 3.8 V), 10 Thermal shutdown, 11 – Charge Safety Timer Expiration

3

BAT_FAULT

x

R

NA

0 – Normal, 1 – BATOVP

2

NTC_FAULT[2]

x

R

NA

1

NTC_FAULT[1]

x

R

NA

0

NTC_FAULT[0]

x

R

NA

JEITA
000 – Normal, 010 – Warm, 011 – Cool, 101 – Cold, 110 – Hot (Buck
mode)
000 – Normal, 101 – Cold, 110 – Hot (Boost mode)

LEGEND: R/W = Read/Write; R = Read only

40

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

bq25601
www.ti.com

SLUSCK5 – MARCH 2017

8.4.11 REG0A
Table 15. REG0A Field Descriptions
Bit

Field

POR

Type

Reset

Description

7

VBUS_GD

x

R

NA

0 – Not VBUS attached,
1 – VBUS Attached

6

VINDPM_STAT

x

R

NA

0 – Not in VINDPM, 1 – in VINDPM

5

IINDPM_STAT

x

R

NA

0 – Not in IINDPM, 1 – in IINDPM

4

Reserved

x

R

NA

3

TOPOFF_ACTIVE

x

R

NA

0 – Top off timer not counting.
1 – Top off timer counting

2

ACOV_STAT

x

R

NA

0 – Device is NOT in ACOV
1 – Device is in ACOV

1

VINDPM_INT_ MASK

0

R/W

by REG_RST

0 - Allow VINDPM INT pulse
1 - Mask VINDPM INT pulse

0

IINDPM_INT_ MASK

0

R/W

by REG_RST

0 - Allow IINDPM INT pulse
1 - Mask IINDPM INT pulse

LEGEND: R/W = Read/Write; R = Read only

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

41

bq25601
SLUSCK5 – MARCH 2017

www.ti.com

8.4.12 REG0B
Table 16. REG0B Field Descriptions
Bit

Field

POR

Type

Reset

Description
Register reset
0 – Keep current register setting
1 – Reset to default register value and reset safety timer
Note: Bit resets to 0 after register reset is completed

7

REG_RST

0

R/W

NA

6

PN[3]

x

R

NA

5

PN[2]

x

R

NA

4

PN[1]

x

R

NA

3

PN[0]

x

R

NA

2

Reserved

x

R

NA

1

DEV_REV[1]

x

R

NA

0

DEV_REV[0]

x

R

NA

bq25601 : 0010

LEGEND: R/W = Read/Write; R = Read only

9 Application and Implementation
NOTE
information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.

9.1 Application information
A typical application consists of the device configured as an I2C controlled power path management device and a
single cell battery charger for Li-Ion and Li-polymer batteries used in a wide range of smart phones and other
portable devices. It integrates an input reverse-block FET (RBFET, Q1), high-side switching FET (HSFET, Q2),
low-side switching FET (LSFET, Q3), and battery FET (BATFET Q4) between the system and battery. The
device also integrates a bootstrap diode for the high-side gate drive.

42

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

bq25601
www.ti.com

SLUSCK5 – MARCH 2017

9.2 Typical Application Diagram
1 H

VAC

SYSTEM
3.5V ± 4.6V

SW

3.9 V ± 13.5 V
VBUS

10 F
47 nF

1 F

BTST

PMID

REGN

10 F

4.7 µF
GND
Opt.
SYS

SYS
SYS
2.2 k
PG
2.2 k
STAT

VREF

bq25601

BAT
10 F

3 x 10 k
REGN

SDA

5.23 k

SCL
TS

Host

+

INT

30.1 k

10 k

CE
QON
PSEL
PHY
Optional

Figure 28. Power Path Management Application
9.2.1 Design Requirements
9.2.2 Detailed Design Procedure
9.2.2.1 inductor Selection
The 1.5-MHz switching frequency allows the use of small inductor and capacitor values to maintain an inductor
saturation current higher than the charging current (ICHG) plus half the ripple current (IRIPPLE):
ISAT ≥ ICHG + (1/2) IRIPPLE

(3)

The inductor ripple current depends on the input voltage (VVBUS), the duty cycle (D = VBAT/VVBUS), the switching
frequency (fS) and the inductance (L).
V ´ D ´ (1 - D)
IRIPPLE = IN
fs ´ L
(4)
The maximum inductor ripple current occurs when the duty cycle (D) is 0.5 or approximately 0.5. Usually inductor
ripple is designed in the range between 20% and 40% maximum charging current as a trade-off between
inductor size and efficiency for a practical design.

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

43

bq25601
SLUSCK5 – MARCH 2017

www.ti.com

Typical Application Diagram (continued)
9.2.2.2 input Capacitor
Design input capacitance to provide enough ripple current rating to absorb input switching ripple current. The
worst case RMS ripple current is half of the charging current when duty cycle is 0.5. If the converter does not
operate at 50% duty cycle, then the worst case capacitor RMS current ICin occurs where the duty cycle is closest
to 50% and can be estimated using Equation 5.

ICIN = ICHG ´ D ´ (1 - D)

(5)

Low ESR ceramic capacitor such as X7R or X5R is preferred for input decoupling capacitor and should be
placed to the drain of the high-side MOSFET and source of the low-side MOSFET as close as possible. Voltage
rating of the capacitor must be higher than normal input voltage level. A rating of 25-V or higher capacitor is
preferred for 15 V input voltage. Capacitance of 22-μF is suggested for typical of 3A charging current.
9.2.2.3 Output Capacitor
Ensure that the output capacitance has enough ripple current rating to absorb the output switching ripple current.
Equation 6 shows the output capacitor RMS current ICOUT calculation.
I
ICOUT = RIPPLE » 0.29 ´ IRIPPLE
2´ 3
(6)
The output capacitor voltage ripple can be calculated as follows:
æ
ö
V
V
DVO = OUT2 ç 1 - OUT ÷
VIN ø
8LCfs è

(7)

At certain input and output voltage and switching frequency, the voltage ripple can be reduced by increasing the
output filter LC.
The charger device has internal loop compensation optimized for & gt; 20μF ceramic output capacitance. The
preferred ceramic capacitor is 10V rating, X7R or X5R.

44

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

bq25601
www.ti.com

SLUSCK5 – MARCH 2017

10 Power Supply Recommendations
in order to provide an output voltage on SYS, the bq25601 device requires a power supply between 3.9 V and
14.2 V input with at least 100-mA current rating connected to VBUS and a single-cell Li-Ion battery with voltage & gt;
VBATUVLO connected to BAT. The source current rating needs to be at least 3 A in order for the buck converter of
the charger to provide maximum output power to SYS.

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

45

bq25601
SLUSCK5 – MARCH 2017

www.ti.com

11 Layout
11.1 Layout Guidelines
The switching node rise and fall times should be minimized for minimum switching loss. Proper layout of the
components to minimize high frequency current path loop (see Figure 29) is important to prevent electrical and
magnetic field radiation and high frequency resonant problems. Follow this specific order carefully to achieve the
proper layout.
1. Place input capacitor as close as possible to PMID pin and GND pin connections and use shortest copper
trace connection or GND plane.
2. Place inductor input pin to SW pin as close as possible. Minimize the copper area of this trace to lower
electrical and magnetic field radiation but make the trace wide enough to carry the charging current. Do not
use multiple layers in parallel for this connection. Minimize parasitic capacitance from this area to any other
trace or plane.
3. Put output capacitor near to the inductor and the device. Ground connections need to be tied to the IC
ground with a short copper trace connection or GND plane.
4. Route analog ground separately from power ground. Connect analog ground and connect power ground
separately. Connect analog ground and power ground together using thermal pad as the single ground
connection point. Or using a 0-Ω resistor to tie analog ground to power ground.
5. Use single ground connection to tie charger power ground to charger analog ground. Just beneath the
device. Use ground copper pour but avoid power pins to reduce inductive and capacitive noise coupling.
6. Place decoupling capacitors next to the IC pins and make trace connection as short as possible.
7. It is critical that the exposed thermal pad on the backside of the device package be soldered to the PCB
ground. Ensure that there are sufficient thermal vias directly under the IC, connecting to the ground plane on
the other layers.
8. Ensure that the number and sizes of vias allow enough copper for a given current path.
See the EVM user's guide SLUUBL3 for the recommended component placement with trace and via locations.
For the VQFN information, refer to SCBA017 and SLUA271.

11.2 Layout Example

+

+
±

Figure 29. High Frequency Current Path

46

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

bq25601
www.ti.com

SLUSCK5 – MARCH 2017

Layout Example (continued)

Figure 30. Layout Example

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

47

bq25601
SLUSCK5 – MARCH 2017

www.ti.com

12 Device and Documentation Support
12.1 Documentation Support
12.1.1 Related Links
The table below lists quick access links. Categories include technical documents, support and community
resources, tools and software, and quick access to sample or buy.

12.2 Community Resources
The following links connect to TI community resources. Linked contents are provided " AS IS " by the respective
contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of
Use.
TI E2E™ Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration
among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help
solve problems with fellow engineers.
Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and
contact information for technical support.

12.3 Trademarks
E2E is a trademark of Texas Instruments.
WEBENCH is a registered trademark of Texas Instruments.

12.4 Electrostatic Discharge Caution
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.

12.5 Glossary
SLYZ022 — TI Glossary.
This glossary lists and explains terms, acronyms, and definitions.

48

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

bq25601
www.ti.com

SLUSCK5 – MARCH 2017

13 Mechanical, Packaging, and Orderable Information
The following pages include mechanical, packaging, and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser-based versions of this data sheet, refer to the left-hand navigation.

Submit Documentation Feedback

Copyright © 2017, Texas Instruments Incorporated

Product Folder Links: bq25601

49

PACKAGE OPTION ADDENDUM

www.ti.com

10-Dec-2020

PACKAGING INFORMATION
Orderable Device

Status
(1)

Package Type Package Pins Package
Drawing
Qty

Eco Plan
(2)

Lead finish/
Ball material

MSL Peak Temp

Op Temp (°C)

Device Marking

(3)

(4/5)

(6)

BQ25601RTWR

ACTIVE

WQFN

RTW

24

3000

RoHS & Green NIPDAU | NIPDAUAG

Level-2-260C-1 YEAR

-40 to 85

BQ25601

BQ25601RTWT

ACTIVE

WQFN

RTW

24

250

RoHS & Green NIPDAU | NIPDAUAG

Level-2-260C-1 YEAR

-40 to 85

BQ25601

(1)

The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)

RoHS: TI defines " RoHS " to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, " RoHS " products are suitable for use in specified lead-free processes. TI may
reference these types of products as " Pb-Free " .
RoHS Exempt: TI defines " RoHS Exempt " to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines " Green " to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of & lt; =1000ppm threshold. Antimony trioxide based
flame retardants must also meet the & lt; =1000ppm threshold requirement.
(3)

MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.

(4)

There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.

(5)

Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a " ~ " will appear on a device. If a line is indented then it is a continuation
of the previous line and the two combined represent the entire Device Marking for that device.
(6)

Lead finish/Ball material - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead finish/Ball material values may wrap to two
lines if the finish value exceeds the maximum column width.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.

Addendum-Page 1

Samples

PACKAGE OPTION ADDENDUM

www.ti.com

10-Dec-2020

Addendum-Page 2

PACKAGE MATERIALS INFORMATION
www.ti.com

17-Oct-2020

TAPE AND REEL INFORMATION

*All dimensions are nominal

Device

Package Package Pins
Type Drawing

SPQ

Reel
Reel
A0
Diameter Width (mm)
(mm) W1 (mm)

B0
(mm)

K0
(mm)

P1
(mm)

W
Pin1
(mm) Quadrant

BQ25601RTWR

WQFN

RTW

24

3000

330.0

12.4

4.35

4.35

1.1

8.0

12.0

Q2

BQ25601RTWR

WQFN

RTW

24

3000

330.0

12.4

4.25

4.25

1.15

8.0

12.0

Q2

BQ25601RTWT

WQFN

RTW

24

250

180.0

12.4

4.25

4.25

1.15

8.0

12.0

Q2

Pack Materials-Page 1

PACKAGE MATERIALS INFORMATION
www.ti.com

17-Oct-2020

*All dimensions are nominal

Device

Package Type

Package Drawing

Pins

SPQ

Length (mm)

Width (mm)

Height (mm)

BQ25601RTWR

WQFN

RTW

24

3000

338.0

355.0

50.0

BQ25601RTWR

WQFN

RTW

24

3000

367.0

367.0

35.0

BQ25601RTWT

WQFN

RTW

24

250

210.0

185.0

35.0

Pack Materials-Page 2

IMPORTANT NOTICE AND DISCLAIMER
TI PROVIDES TECHNICAL AND RELIABILITY DATA (INCLUDING DATASHEETS), DESIGN RESOURCES (INCLUDING REFERENCE
DESIGNS), APPLICATION OR OTHER DESIGN ADVICE, WEB TOOLS, SAFETY INFORMATION, AND OTHER RESOURCES “AS IS”
AND WITH ALL FAULTS, AND DISCLAIMS ALL WARRANTIES, EXPRESS AND IMPLIED, INCLUDING WITHOUT LIMITATION ANY
IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT OF THIRD
PARTY INTELLECTUAL PROPERTY RIGHTS.
These resources are intended for skilled developers designing with TI products. You are solely responsible for (1) selecting the appropriate
TI products for your application, (2) designing, validating and testing your application, and (3) ensuring your application meets applicable
standards, and any other safety, security, or other requirements. These resources are subject to change without notice. TI grants you
permission to use these resources only for development of an application that uses the TI products described in the resource. Other
reproduction and display of these resources is prohibited. No license is granted to any other TI intellectual property right or to any third
party intellectual property right. TI disclaims responsibility for, and you will fully indemnify TI and its representatives against, any claims,
damages, costs, losses, and liabilities arising out of your use of these resources.
TI’s products are provided subject to TI’s Terms of Sale (www.ti.com/legal/termsofsale.html) or other applicable terms available either on
ti.com or provided in conjunction with such TI products. TI’s provision of these resources does not expand or otherwise alter TI’s applicable
warranties or warranty disclaimers for TI products.
Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265
Copyright © 2020, Texas Instruments Incorporated