Popatrz w załaczniki: -datasheet SOP10- (10-pin) Green-Mode PFC/PWM Combo CONTROLLER CM6806+ The sign + is only "plus", both CM6806AG and CM6806BG are CM6806+X http://obrazki.elektroda.pl/3446462800_1490036687_thumb.jpg Poczytaj temat Link ATX with CM6806+X from Chieftec APS-100CB * poprawka : równolegle do C23 dostawić elektrolityczny kondensator 2,2uF/25V http://obrazki.elektroda.pl/3711432200_1490037101_thumb.jpg Pomiary napięć na pinach (sprawnego ATX) z CM6806+X ON\ Stb pin.1 GND GND pin.2 IAC INPUT-PFC IN VOLTAGE 0.7V\ 0V pin.3 I SENSE INPUT 0V\0V pin.4 VEAO VOLTAGE ERROR 1.1V\ 0V AMPLIFIER OUT pin.5 VFB INPUT-PFC OUT VOLTAGE 1,9-2.4V\0V pin.6 V+I INPUT-feedback PWM+LIMIT 1.3- 1,9V\0V pin.7 PWM FAULT INPUT=PWM SHORT,OVP 3,8V\0V pin.8 Vcc 10V<13-15V<18V 14.V\0V pin.9 PFC OUT DRIVER\PULSE 2.3V\0V pin.10 PWM OUT DRIVER\PULSE 2,4- 4.6V\0V * pin5 5 Vfb (C23 , R14=19.6k ) ... komparator Vin-OK (<2.5V) * przy obecnoścci imp. na PWM(10) 1= GND 2= 2,2- 2,7V (IAC) 3=0.01v (Isense) 4=0.04V 5=2V (VFB) 6=0.24V(V+I) 7=3.2V fault 8=15.75v VCC 9=0v PFC 10=6.95V
CM6805(A;B;C)/CM6806(A;B;C)
(ABC0401A03A/03C/05A ; ABC0401A06A/01B)
10-PIN Green-Mode PFC/PWM Combo CONTROLLER for High Density AC Adapter
GENERAL DESCRIPTION
FEATURES
The CM6805A and CM6806A series are monolithic ICs
Patent Filed #5,565,761, #5,747,977, #5,742,151,
without software embedded, the Green-Mode PFC/PWM
#5,804,950, #5,798,635
Combo controller for High Density AC Adapter. For the
Both PFC and PWM have the Green Mode to meet blue
power supply less than 200Watt, its input current shaping
angel and energy star spec.
PFC performance could be very close to the performance of
10-Pin SOIC package
the CM6800 or ML4800 leading edge modulation average
PWM pulse skipping for the green mode
current topology.
Use RAC as the Startup resistor which can be & gt; 2000K or
higher at IAC pin
CM6805A/CM6806A offers the use of smaller, lower cost
It can use the HV bipolar to start up the chip and it helps
bulk capacitors, reduces power line loading and stress on
green mode.
the switching FETs, and results in a power supply fully
Easy to configure into Boost Follower
compliant to IEC1000-3-2 specifications. The CM6805A /
Enable lowest BOM for power supply with PFC
CM6806A includes circuits for the implementation of a
Internally synchronized PFC and PWM in one IC
leading edge, input current shaping technique “boost” type
Patented slew rate enhanced voltage error amplifier with
PFC and a trailing edge, PWM.
advanced input current shaping technique
Universal Line Input Voltage
The CM6805A’s PFC and PWM operate at the same
CCM boost or DCM boost with leading edge modulation
frequency, 67.5kHz. A PFC OVP comparator shuts down
PFC using Input Current Shaping Technique
the PFC section in the event of a sudden decrease in load.
Feedforward IAC pin to do the automatic slope
The PFC section also includes peak current limiting for
compensation
enhanced system reliability.
PFCOVP, VCCOVP, Precision -1V PFC ILIMIT, PFC
Tri-Fault Detect comparator to meet UL1950
Both PFC and PWM have the Green Mode Functions.
Low supply currents; start-up: 100uA typical, operating
When the load is below GMth, Green Mode Threshold,
current: 2mA typical.
PFCOUT is turned off. The GMth can be programmed by
Synchronized leading PFC and trailing edge modulation
the designer. PWM Green Mode will happen when the
PWM to reduce ripple current in the storage capacitor
PWMCMP (PWM Comparator) Duty Cycle is less than ~
between the PFC and PWM sections and to reduce
6%, in the next cycle, the PWMOUT pulse will be removed
switching noise in the system
until PWMCMP Duty Cycle is greater than 6%, then the
VINOK Comparator to guarantee to enable PWM when
next cycle, PWMOUT pulse appears.
PFC reach steady state
High efficiency trailing-edge current mode PWM
PWM has a PWMtrifault pin which can sense the PWM
Exact 50% PWM maximum duty cycle
short and determine the GMth to turn off PFC.
UVLO, REFOK, and brownout protection
Digital PFC and PWM soft start, ~10mS
Precision PWM 1.5V current limit for current mode
operation
PWMtrifault to sense DC to DC short and Turn off PFC at
GMth
PWMtrifault also can be programmed to do the Thermal
Protection
2005/12/28
Preliminary
Champion Microelectronic Corporation
Page 1
CM6805(A;B;C)/CM6806(A;B;C)
(ABC0401A03A/03C/05A ; ABC0401A06A/01B)
10-PIN Green-Mode PFC/PWM Combo CONTROLLER for High Density AC Adapter
APPLICATIONS
PIN CONFIGURATION
10 Pin SSOP (R10)
Top View
AC Adaptor
Open Frame
1
GND
PWM OUT
10
2
IAC
PFC OUT
9
3
ISENSE
VCC
8
4
VEAO
PWMTRIFAULT
7
5
VFB
V+I
6
PIN DESCRIPTION
Pin No.
Symbol
Description
1
GND
IAC
Feedforward input to do slope compensation and to start up
Operating Voltage
Typ.
Max.
Unit
Ground
2
Min.
0
1
V
-5
0.7
V
0
6
V
3
V
the system. During the start up, IAC is connected to VCC until
VCC is greater than 13V.
3
ISENSE
4
VEAO
5
VFB
PFC transconductance voltage error amplifier input
0
6
V+I
PWM current limit comparator input
0
1.5
V
7
PWMTRIFAULT
PWMTRIFAULT input; it can sense PWM Short or OVP
0
VCC
V
8
VCC
Positive supply
10
18
V
9
PFC OUT
PFC driver output
0
VCC
V
10
PWM OUT
PWM driver output
0
VCC
V
2005/12/28
Current sense input to the PFC current limit comparator
PFC transconductance voltage error amplifier output
Preliminary
Champion Microelectronic Corporation
2.5
Page 2
CM6805(A;B;C)/CM6806(A;B;C)
(ABC0401A03A/03C/05A ; ABC0401A06A/01B)
10-PIN Green-Mode PFC/PWM Combo CONTROLLER for High Density AC Adapter
ORDERING INFORMATION
Part Number
Operation Frequency
Initial Accuracy (KHz)
Min
Typ
Temperature Range
Package
Max
CM6805IR/GIR*
Fpwm = Fpfc = 50Khz
45
50
55
-40℃ to 125℃
10 Pin SSOP(R10)
CM6805AIR/AGIR*
Fpwm = Fpfc = 67.5Khz
60
67
74
-40℃ to 125℃
10 Pin SSOP(R10)
CM6805BIR/BGIR* Fpwm = Fpfc = 100Khz
90
100
110
-40℃ to 125℃
10 Pin SSOP(R10)
CM6805CIR/CGIR* Fpwm = Fpfc = 135Khz
121
135
149
-40℃ to 125℃
10 Pin SSOP(R10)
CM6806IR/GIR*
Fpwm = 2Fpfc = 100Khz
90
100
110
-40℃ to 125℃
10 Pin SSOP(R10)
CM6806AIR/AGIR*
Fpwm = 2Fpfc = 135Khz
121
135
149
-40℃ to 125℃
10 Pin SSOP(R10)
CM6806BIR/BGIR* Fpwm = 2Fpfc = 200Khz
180
200
220
-40℃ to 125℃
10 Pin SSOP(R10)
CM6806CIR/CGIR* Fpwm = 2Fpfc = 270Khz
243
270
297
-40℃ to 125℃
10 Pin SSOP(R10)
Note:
1.G : Suffix for Pb Free Product
2.Initial Accuracy : TA=25℃
2005/12/28
Preliminary
Champion Microelectronic Corporation
Page 3
CM6805(A;B;C)/CM6806(A;B;C)
(ABC0401A03A/03C/05A ; ABC0401A06A/01B)
10-PIN Green-Mode PFC/PWM Combo CONTROLLER for High Density AC Adapter
BLOCK DIAGRAM
4
2
.VEAO
IAC
. R1B
1
1
. R1A
1
IAC
R1C
2
-
ISENSE
3
2
2
.
VCC
8
PFC CMP
UVB
.
VCC
.
-
+
.
5
-
Q
R
GMV
R
.
.
2.5V
S
+
V To Ramp
VFB
Q
.
UVB
+
9
VREFDK
FAULT
PFCOUT
VCC OVP
+
18V
16.4V
-
.
UVLO
VCC
.
-
BROKENWIRE
PFCCLK
.
.
0.5V
PWMCLK
+
.
.
PFC CLK
PWM CLK
fpfc=70KHz
CM6805 fpwm=67.5KHz
CM6806 fpwm=135KHz
PFC OVP
+
2.75V
2.5V
-
.
VIN-OK
VFB
-
PFC ILIMIT
PWMTRIFAULT
VCC-0.7V
R2
UVB
Q
10
VREFDK
+
+
-1V
Q
R1
.
-
0.75V
.
S
+
2.5V
PWMOUT
PWM SHORT
GREEMPWM
GND
-
7
PWMFAULT
+
-
(VCC-1.4V)/2
V=17uA
10mS
GREENMODE
1.5V
PWMCLK
.
.
GND
SS
-
PWM CMP
1
GND
.
+
PROTECTED BY PATENT
SOFT START
6
V+I
ABSOLUTE MAXIMUM RATINGS
Absolute Maximum ratings are those values beyond which the device could be permanently damaged.
Parameter
VCC MAX
IAC (after start up)
ISENSE Voltage
PFC OUT
PWM OUT
VEAO
PWMTrifault
Voltage on Any Other Pin
ICC Current (Average)
Peak PFC OUT Current, Source or Sink
Peak PWM OUT Current, Source or Sink
PFC OUT, PWM OUT Energy Per Cycle
Junction Temperature
Storage Temperature Range
Operating Temperature Range
Lead Temperature (Soldering, 10 sec)
Thermal Resistance (θJA)
2005/12/28
Preliminary
Min.
GND-0.3
-5
GND – 0.3
GND – 0.3
0
GND – 0.3
Max.
20
1.0
0.7
VCC + 0.3
VCC + 0.3
6.3
VCC + 0.3
Units
V
V
V
V
V
V
V
GND-0.3
VCC + 0.3
V
40
0.5
0.5
1.5
150
150
125
260
80
mA
A
A
µJ
℃
℃
℃
℃
℃/W
-65
-40
Champion Microelectronic Corporation
Page 4
CM6805(A;B;C)/CM6806(A;B;C)
(ABC0401A03A/03C/05A ; ABC0401A06A/01B)
10-PIN Green-Mode PFC/PWM Combo CONTROLLER for High Density AC Adapter
ELECTRICAL CHARACTERISTICS
Unless otherwise stated, these specifications apply Vcc=+14V,
TA=Operating Temperature Range (Note 1)
Symbol
Parameter
Test Conditions
CM6805A/CM6806A
Min.
Unit
Typ.
Max.
5
V
65
90
µmho
2.5
2.56
V
-0.5
-1.0
µA
Voltage Error Amplifier (gmv)
Input Voltage Range
Transconductance
0
VNONINV = VINV, VEAO = 3.75V
Feedback Reference Voltage
Input Bias Current
30
2.43
Note 2
Output High Voltage
5.8
Output Low Voltage
Sink Current
Source Current
6.0
V
0.1
VFB = 1.5V, VEAO = 1.5V
0.4
V
-35
VFB = 3V, VEAO = 6V
-20
µA
30
Open Loop Gain
40
µA
50
60
dB
11V & lt; VCC & lt; 16.5V
50
60
dB
Input Impedance
IAC
ISENSE = 0V, TA=25℃
4080
5100
8000
Ohm
Input Impedance (CM6806/06A)
ISENSE = 0V, TA=25℃
35
40
45
K
Threshold Voltage
17.3
17.9
18.5
V
Hysteresis
1.3
1.5
1.75
V
2.64
2.77
2.85
V
300
mV
-1
-0.88
V
150
300
ns
2.30
2.45
2.55
V
1.65
1.75
1.85
V
Power Supply Rejection Ratio
VCC OVP Comparator
PFC OVP Comparator
Threshold Voltage
Hysteresis
230
PFC ILIMIT Comparator
Threshold Voltage
-1.15
Delay to Output
VIN OK Comparator
Threshold Voltage
Hysteresis
PWM Digital Soft Start
Digital Soft Start Timer (Note 2)
Right After Start Up
10
ms
V + I Comparator
Threshold Voltage
Normal operation without soft start
1.38
1.5
1.62
V
150
300
Ns
100
150
200
mV
2.70
2.77
2.85
V
2
4
ms
0.5
0.6
V
VCC-0.1
V
Delay to Output (Note 2)
Threshold Voltage
During soft start condition
PFC Tri-Fault Detect Comparator
Fault Detect HIGH
Time to Fault Detect HIGH
VFB=VFAULT DETECT LOW to VFB = OPEN,
470pF from VFB to GND
Fault Detect LOW
0.4
PWM Tri-Fault Detect Comparator
DC to DC Short
Sweep PWMtrifault
DC to DC OVP
Sweep PWMtrifault
VCC-0.9
-400mV+
(VCC-1.
4)/2
2005/12/28
Preliminary
Champion Microelectronic Corporation
(VCC-1.4)
/2
+400mV
+(VCC-1
.4)/2
Page 5
V
CM6805(A;B;C)/CM6806(A;B;C)
(ABC0401A03A/03C/05A ; ABC0401A06A/01B)
10-PIN Green-Mode PFC/PWM Combo CONTROLLER for High Density AC Adapter
ELECTRICAL CHARACTERISTICS
(Conti.)Unless otherwise stated, these specifications apply
Vcc=+15V, RT = 52.3kΩ, CT = 470pF,TA=Operating Temperature Range (Note 1)
Symbol
Parameter
Test Conditions
CM6805A/CM6806A
Min.
Typ.
Max.
Unit
Oscillator
Voltage Stability
10V & lt; VCC & lt; 15V
1
2
Temperature Stability
Total Variation
Line, Temp
%
%
60
67
74.5
kHz
0.3
PFC Dead Time (Note 2)
0.45
0.65
us
1
%
PFC
Minimum Duty Cycle
IAC=100uA,VFB=2.55V, ISENSE = 0V
Maximum Duty Cycle
IAC=0uA,VFB=2.0V, ISENSE = 0V
90
Output Low Rdson
95
%
15
ohm
0.8
1.5
V
IOUT = -10mA, VCC = 8V
0.4
0.8
V
30
Output Low Voltage
22.5
IOUT = -100mA
45
ohm
Output High Rdson
Output High Voltage
IOUT = 100mA, VCC = 15V
Rise/Fall Time (Note 2)
13.5
V
50
CL = 1000pF
14.2
ns
PWM
Duty Cycle Range
IC
0-46
Output Low Rdson
0-50
%
15
ohm
0.8
1.5
V
IOUT = -10mA, VCC = 8V
0.7
1.5
V
30
Output Low Voltage
22.5
IOUT = -100mA
45
ohm
Output High Rdson
Output High Voltage
IOUT = 100mA, VCC = 15V
Rise/Fall Time (Note 2)
13.5
V
50
CL = 1000pF
14.2
ns
Supply
Start-Up Current
VCC = 11V, CL = 0
Operating Current
100
VCC = 15V, CL = 0
150
uA
2
4.0
mA
Undervoltage Lockout Threshold
12.35
13
13.65
V
Undervoltage Lockout Hysteresis
2.7
3
3.3
V
Note 1: Limits are guaranteed by 100% testing, sampling, or correlation with worst-case test conditions.
Note 2: Guaranteed by design, not 100% production test.
2005/12/28
Preliminary
Champion Microelectronic Corporation
Page 6
CM6805(A;B;C)/CM6806(A;B;C)
(ABC0401A03A/03C/05A ; ABC0401A06A/01B)
10-PIN Green-Mode PFC/PWM Combo CONTROLLER for High Density AC Adapter
TYPICAL PERFORMANCE CHARACTERISTIC
127
Transconductance (umho)
120
113
106
99
92
85
78
71
64
57
2
2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9
3
VFB (V)
Voltage Error Amplifier (gmv) Transconductance
2005/12/28
Preliminary
Champion Microelectronic Corporation
Page 7
CM6805(A;B;C)/CM6806(A;B;C)
(ABC0401A03A/03C/05A ; ABC0401A06A/01B)
10-PIN Green-Mode PFC/PWM Combo CONTROLLER for High Density AC Adapter
Functional Description
The CM6805A/CM6806A consists of an ICST (Input
Current Shaping Technique), CCM (Continuous Conduction
Mode) or DCM (Discontinuous Conduction Mode) boost
PFC (Power Factor Correction) front end and a
synchronized PWM (Pulse Width Modulator) back end. The
CM6805A /CM6806A is designed to replace FAN6803 (8
pin SOP package), which is the second generation of the
ML4803 with 8 pin package. It is distinguished from earlier
combo controllers by its low count, innovative input current
shaping technique, and very low start-up and operating
currents. The PWM section is dedicated to peak current
mode operation. It uses conventional trailing-edge
modulation, while the PFC uses leading-edge modulation.
This patented Leading Edge/Trailing Edge (LETE)
modulation technique helps to minimize ripple current in the
PFC DC buss capacitor.
The main improvements from ML4803 are:
1.
Add Green Mode Functions for both PFC and PWM
2.
Remove the one pin error amplifier and add back the
slew rate enhancement gmv, which is using voltage
input instead of current input. This transconductance
amplifier will increase the transient response 5 to 10
times from the conventional OP
3.
VFB PFC OVP comparator
4.
PFC Tri-Fault Detect for UL1950 compliance and
enhanced safety
5.
A feedforward signal from IAC pin is added to do the
automatic slope compensation. This increases the
signal to noise ratio during the light load; therefore,
THD is improved at light load and high input line
voltage.
6.
CM6805A/CM6806A does not require the bleed
resistor and it uses the more than 800k ohm resistor
between IAC pin and rectified line voltage to feed the
initial current before the chip wakes up.
7.
VINOK comparator is added to guaranteed PWM
cannot turn on until VFB reaches 2.5V in which PFC
boost output is about steady state, typical 380V.
8.
A 10mS digital PWM soft start circuit is added
9.
10 pin SOP package
10. No internal Zener but with VCCOVP comparator
The CM6805A/CM6806A operates both PFC and PWM
sections at 67kHz. This allows the use of smaller PWM
magnetic and output filter components, while minimizing
switching losses in the PFC stage.
Several protection features have been built into the
CM6805A/CM6806A. These include soft-start, redundant
PFC overvoltage protection, PFC Tri-Fault Detect, VINOK,
peak current limiting, duty cycle limiting, under-voltage
lockout, reference ok comparator and VCCOVP.
2005/12/28
Preliminary
Detailed Pin Descriptions
IAC (Pin 2)
Typically, it has a feedforward resistor, RAC, 800K~5KK ohm
resistor connected between this pin and rectified line input
voltage.
This pin serves 2 purposes:
1.) During the startup condition, it supplies the startup
current; therefore, the system does not requires
additional bleed resistor to start up the chip.
2.) The current of RAC will program the automatic
slope compensation for the system. This
feedforward signal can increase the signal to noise
ratio for the light load condition or the high input line
voltage condition.
Optional Resistor between IAC and VCC:
This resistor is about 100K ohm, it can improve the THD
of the input current at high line and light load
ISENSE (Pin 3)
This pin ties to a resistor which senses the PFC input
current. This signal should be negative with respect to the IC
ground. It internally feeds the pulse-by-pulse current limit
comparator and the current sense feedback signal. The
ILIMIT trip level is –1V. The ISENSE feedback is internally
multiplied by a gain of four and compared against the internal
programmed ramp to set the PFC duty cycle. The
intersection of the boost inductor current downslope with the
internal programming ramp determines the boost off-time.
It requires a RC filter between ISENSE and PFC boost
sensing resistor.
VEAO (Pin 4)
This is the PFC slew rate enhanced transconductance
amplifier output which needs to connected with a
compensation network Ground.
VFB (Pin 5)
Besides this is the PFC slew rate enhanced
transconductance input, it also tie to a couple of protection
comparators, PFCOVP, and PFC Tri-Fault Detect
V + I (Pin 6)
This pin is tied to the primary side PWM current sense
resistor or transformer. It provides the internal pulse-by-pulse
current limit for the PWM stage (which occurs at 1.5V) and
the peak current mode feedback path for the current mode
control of the PWM stage. Besides current information, the
optocouple also goes into V + I pin. Therefore, it is the SUM
Amplifier input.
Soft Start can be triggered by the following conditions:
1.) During the startup (VCC is less than 10V)
2.) DC to DC short (PWMtrifault is greater thanVCC-0.7V)
Champion Microelectronic Corporation
Page 8
CM6805(A;B;C)/CM6806(A;B;C)
(ABC0401A03A/03C/05A ; ABC0401A06A/01B)
10-PIN Green-Mode PFC/PWM Combo CONTROLLER for High Density AC Adapter
PWMtrifault (Pin 7)
This pin is to monitor the DC to DC faults. PWMtrifault
monitors the voltage which is translated by the photocouple
output current. When the output is short, photocouple and
TL431 will not draw any current and PWMtrifault will go
toward VCC.
When PWMtrifault is above VCC-0.7V, the soft start will be
triggered and PWMOUT is turned off. When the load is
lighter, the TL431 will increase the Photocouple current.
When PWMtrifault is below (VCC-1.4)/2, which means it is
below GMth, Green Mode Threshold. PFCOUT will be
turned off due the load is below GMth. The GMth can be
programmed by the user. Typical the GMth is 20% of the
full load.
VCC (Pin 8)
VCC is the power input connection to the IC. The VCC
start-up current is 100uA. The no-load ICC current is 2mA.
VCC quiescent current will include both the IC biasing
currents and the PFC and PWM output currents. Given the
operating frequency and the MOSFET gate charge (Qg),
average PFC and PWM output currents can be calculated
as IOUT = Qg x F. The average magnetizing current
required for any gate drive transformers must also be
included. The VCC pin is also assumed to be proportional
to the PFC output voltage. Internally it is tied to the VCC
OVP comparator (17.9V) providing redundant high-speed
over-voltage protection (OVP) of the PFC stage. VCC also
ties internally to the UVLO circuitry and VREFOK
comparator, enabling the IC at 13V and disabling it at 10V.
VCC must be bypassed with a high quality ceramic bypass
capacitor placed as close as possible to the IC. Good
bypassing is critical to the proper operation of the
CM6805A/CM6806A.
VCC is typically produced by an additional winding off the
boost inductor or PFC Choke, providing a voltage that is
proportional to the PFC output voltage. Since the VCC OVP
max voltage is 17.9V, an internal shunt limits VCC
overvoltage to an acceptable value. An external clamp,
such as shown in Figure 1, is desirable but not necessary.
VCC
PFCOUT (Pin 9) and PWM OUT (Pin 10)
PFC OUT and PWM OUT are the high-current power driver
capable of directly driving the gate of a power MOSFET with
peak currents up to -1A and +0.5A. Both outputs are actively
held low when VCC is below the UVLO threshold level which
is 15V or VREFOK comparator is low.
Power Factor Correction
Power factor correction makes a nonlinear load look like a
resistive load to the AC line. For a resistor, the current drawn
from the line is in phase with and proportional to the line
voltage, so the power factor is unity (one). A common class
of nonlinear load is the input of most power supplies, which
use a bridge rectifier and capacitive input filter fed from the
line. The peak-charging effect, which occurs on the input
filter capacitor in these supplies, causes brief high-amplitude
pulses of current to flow from the power line, rather than a
sinusoidal current in phase with the line voltage. Such
supplies present a power factor to the line of less than one
(i.e. they cause significant current harmonics of the power
line frequency to appear at their input). If the input current
drawn by such a supply (or any other nonlinear load) can be
made to follow the input voltage in instantaneous amplitude,
it will appear resistive to the AC line and a unity power factor
will be achieved.
To hold the input current draw of a device drawing power
from the AC line in phase with and proportional to the input
voltage, a way must be found to prevent that device from
loading the line except in proportion to the instantaneous line
voltage. The PFC section of the CM6805A/CM6806A uses a
boost-mode DC-DC converter to accomplish this. The input
to the converter is the full wave rectified AC line voltage. No
bulk filtering is applied following the bridge rectifier, so the
input voltage to the boost converter ranges (at twice line
frequency) from zero volts to the peak value of the AC input
and back to zero.
By forcing the boost converter to meet two simultaneous
conditions, it is possible to ensure that the current draws
from the power line matches the instantaneous line voltage.
One of these conditions is that the output voltage of the
boost converter must be set higher than the peak value of
the line voltage. A commonly used value is 385VFB, to allow
for a high line of 270VACrms. The other condition is that the
current that the converter is allowed to draw from the line at
any given instant must be proportional to the line voltage.
1N5250B
GND
Figure 1. Optional VCC Clam p
This limits the maximum VCC that can be applied to the IC
while allowing a VCC which is high enough to trip the VCC
OVP. An RC filter at VCC is required between boost trap
winding and VCC.
2005/12/28
Preliminary
Champion Microelectronic Corporation
Page 9
CM6805(A;B;C)/CM6806(A;B;C)
(ABC0401A03A/03C/05A ; ABC0401A06A/01B)
10-PIN Green-Mode PFC/PWM Combo CONTROLLER for High Density AC Adapter
2005/12/28
Preliminary
Champion Microelectronic Corporation
Page 10
CM6805(A;B;C)/CM6806(A;B;C)
(ABC0401A03A/03C/05A ; ABC0401A06A/01B)
10-PIN Green-Mode PFC/PWM Combo CONTROLLER for High Density AC Adapter
PFC Control: Leading Edge Modulation with Input
Current Shaping Technique
(I.C.S.T.)
The only differences between the conventional PFC control
topology and I.C.S.T. is:
the current loop of the conventional control method is a
close loop method and it requires a detail understanding
about the system loop gain to design. With I.C.S.T., since
the current loop is an open loop, it is very straightforward to
implement it.
The end result of the any PFC system, the power supply is
like a pure resistor at low frequency. Therefore, current is in
phase with voltage.
In the conventional control, it forces the input current to
follow the input voltage. In CM6805A/CM6806A, the chip
thinks if a boost converter needs to behave like a low
frequency resistor, what the duty cycle should be.
The following equations is CM6805A/CM6806A try to
achieve:
Re =
Vin
(1)
I in
I l = I in
(2)
Equation 2 means: average boost inductor current equals
to input current.
∴Vin × I l ≈ Vout × I d
(3)
Therefore, input instantaneous power is about to equal to
the output instantaneous power.
For steady state and for the each phase angle, boost
converter DC equation at continuous conduction mode is:
Vout
Vin
= 1
Therefore, equation (6) becomes:
Id =
I d × toff
Tsw
= I d × d ' = I d × (1 − d )
(7)
Combine equation (7) and equation (5), and we get:
Id × d ' =
∴ Id =
∴ Id =
( d ' ) 2 × Vout
d × Vout
Re
'
Re
(8)
Vout toff
×
Re Tsw
From this simple equation (8), we implement the PFC control
section of the CM6805A/CM6806A.
Leading/Trailing Modulation
Conventional Pulse Width Modulation (PWM) techniques
employ trailing edge modulation in which the switch will turn
ON right after the trailing edge of the system clock. The error
amplifier output is then compared with the modulating ramp.
When the modulating ramp reaches the level of the error
amplifier output voltage, the switch will be turned OFF. When
the switch is ON, the inductor current will ramp up. The
effective duty cycle of the trailing edge modulation is
determined during the ON time of the switch. Figure 2 shows
a typical trailing edge control scheme.
In case of leading edge modulation, the switch is turned OFF
right at the leading edge of the system clock. When the
modulating ramp reaches the level of the error amplifier
output voltage, the switch will be turned ON. The effective
duty-cycle of the leading edge modulation is determined
during OFF time of the switch. Figure 3 shows a leading
edge control scheme.
(4)
(1 − d )
Rearrange above equations, (1), (2),(3), and (4) in term of
Vout and d, boost converter duty cycle and we can get
average boost diode current equation (5):
Id =
(1 − d ) 2 × Vout
Re
(5)
Also, the average diode current can be expressed as:
Id =
1
Tsw
∫
Toff
0
I d (t ) ⋅ dt
(6)
If the value of the boost inductor is large enough, we can
assume
I d (t ) ~ I d .
It means during each cycle or we
can say during the sampling, the diode current is a
constant.
2005/12/28
Preliminary
Champion Microelectronic Corporation
Page 11
CM6805(A;B;C)/CM6806(A;B;C)
(ABC0401A03A/03C/05A ; ABC0401A06A/01B)
10-PIN Green-Mode PFC/PWM Combo CONTROLLER for High Density AC Adapter
2005/12/28
Preliminary
Champion Microelectronic Corporation
Page 12
CM6805(A;B;C)/CM6806(A;B;C)
(ABC0401A03A/03C/05A ; ABC0401A06A/01B)
10-PIN Green-Mode PFC/PWM Combo CONTROLLER for High Density AC Adapter
One of the advantages of this control technique is that it
required only one system clock. Switch 1(SW1) turns OFF
and switch 2 (SW2) turns ON at the same instant to
minimize the momentary “no-load” period, thus lowering
ripple voltage generated by the switching action. With such
synchronized switching, the ripple voltage of the first stage
is reduced. Calculation and evaluation have shown that the
120Hz component of the PFC’s output ripple voltage can be
reduced by as much as 30% using this method,
substantially reducing dissipation in the high-voltage PFC
capacitor.
Typical Applications
ZCV: Compensation Net Work for the Voltage Loop
GMv: Transconductance of VEAO
PIN: Average PFC Input Power
VOUTDC: PFC Boost Output Voltage; typical designed value is
380V.
CDC: PFC Boost Output Capacitor
∆VEAO: This is the necessary change of the VEAO to deliver
the designed average input power. The average value is
6V-3V=3V since when the input line voltage increases, the
delta VEAO will be reduced to deliver the same to the output.
To over compensate, we choose the delta VEAO is 3V.
PFC Section:
PFC Voltage Loop Error Amp, VEAO
The ML4803 utilizes an one pin voltage error amplifier in
the PFC section (VEAO). In the CM6805A/CM6806A, it is
using the slew rate enhanced transconductance amplifier,
which is the same as error amplifier in the CM6800. The
unique transconductance profile can speed up the
conventional transient response by 10 times. The internal
reference of the VEAO is 2.5V. The input of the VEAO is
VFB pin.
Internal Voltage Ramp
The internal ramp current source is programmed by way of
VEAO pin voltage. When VEAO increases the ramp current
source is also increase. This current source is used to
develop the internal ramp by charging the internal 30pF +12/
-10% capacitor. The frequency of the internal programming
ramp is set internally to 67kHz.
PFC Voltage Loop Compensation
The voltage-loop bandwidth must be set to less than 120Hz
to limit the amount of line current harmonic distortion. A
typical crossover frequency is 30Hz.
There are 2 purposes to add a filter at ISENSE pin:
1.) Protection: During start up or inrush current
conditions, it will have a large voltage cross Rs,
which is the sensing resistor of the PFC boost
converter. It requires the ISENSE Filter to attenuate
the energy.
2.) Reduce L, the Boost Inductor: The ISENSE Filter
also can reduce the Boost Inductor value since the
ISENSE Filter behaves like an integrator before
going ISENSE which is the input of the current error
amplifier, IEAO.
The Voltage Loop Gain (S)
∆VOUT ∆VFB ∆VEAO
*
*
∆VEAO ∆VOUT ∆VFB
PIN * 2.5V
≈
* GMV * ZCV
2
VOUTDC * ∆VEAO * S * CDC
=
2005/12/28
Preliminary
Design PFC ISENSE Filtering
ISENSE Filter, the RC filter between Rs and ISENSE:
Champion Microelectronic Corporation
Page 13
CM6805(A;B;C)/CM6806(A;B;C)
(ABC0401A03A/03C/05A ; ABC0401A06A/01B)
10-PIN Green-Mode PFC/PWM Combo CONTROLLER for High Density AC Adapter
The ISENSE Filter is a RC filter. The resistor value of the
ISENSE Filter is between 100 ohm and 50 ohm. By selecting
RFILTER equal to 50 ohm will keep the offset of the IEAO less
than 5mV. Usually, we design the pole of ISENSE Filter at
fpfc/6, one sixth of the PFC switching frequency. Therefore,
the boost inductor can be reduced 6 times without
disturbing the stability. Therefore, the capacitor of the ISENSE
Filter, CFILTER, will be around 283nF.
IAC, RAC, Automatic Slope Compensation, DCM at high line
and light load, and Startup current
There are 4 purposes for IAC pin:
1.) For the leading edge modulation, when the duty
cycle is less than 50%, it requires the similar slope
compensation, as the duty cycle of the trailing
edge modulation is greater than 50%. In the
CM6805A/CM6806A, it is a relatively easy thing to
design. Use an more than 800K ohm resistor, RAC
to connect IAC pin and the rectified line voltage. It
will do the automatic slope compensation. If the
input boost inductor is too small, the RAC may
need to be reduced more.
2.) During the startup period, Rac also provides the
initial startup current, 100uA;therefore, the bleed
resistor is not needed.
3.) Since IAC pin with RAC behaves as a feedforward
signal, it also enhances the signal to noise ratio
and the THD of the input current.
4.) It also will try to keep the maximum input power to
be constant. However, the maximum input power
will still go up when the input line voltage goes up.
Start Up of the system, UVLO, VREFOK and Soft Start
During the Start-up period, RAC resistor will provide the start
up current~100uA from the rectified line voltage to IAC pin.
Inside of CM6805A/CM6806A during the start-up period,
IAC is connected to VCC until the VCC reaches UVLO
voltage which is 15V and internal reference voltage is
stable, it will disconnect itself from VCC. During the Start
up, the soft start function is triggered and the duration of the
soft start will last around 10mS.
PFC section wakes up after Start up period
After Start up period, PFC section will softly start since
VEAO is zero before the start-up period. Since VEAO is a
slew rate enhanced transconductance amplifier (see figure
3), VEAO has a high impedance output like a current
source and it will slowly charge the compensation net work
which needs to be designed by using the voltage loop gain
equation.
Before PFC boost output reaches its design voltage, it is
around 380V and VFB reaches 2.5V, PWM section is off.
2005/12/28
Preliminary
PWM section wakes up after PFC reaches steady state
PWM section is off all the time before PFC VFB reaches
2.45V. Then internal 10mS digital PWM soft start circuit
slowly ramps up the soft-start voltage.
PFC OVP Comparator
PFC OVP Comparator sense VFB pin which is the same the
voltage loop input. The good thing is the compensation
network is connected to VEAO. The PFC OVP function is a
relative fast OVP. It is not like the conventional error amplifier
which is an operational amplifier and it requires a local
feedback and it make the OVP action becomes very slow.
The threshold of the PFC OVP is 2.5V+10% =2.75V with
250mV hysteresis.
PFC Tri-Fault Detect Comparator
To improve power supply reliability, reduce system
component count, and simplify compliance to UL1950 safety
standards, the CM6805A/CM6806A includes PFC Tri-Fault
Detect. This feature monitors VFB (Pin 5) for certain PFC
fault conditions.
In case of a feedback path failure, the output of the PFC
could go out of safe operating limits. With such a failure, VFB
will go outside of its normal operating area. Should VFB go
too low, too high, or open, PFC Tri-Fault Detect senses the
error and terminates the PFC output drive.
PFC Tri-Fault detect is an entirely internal circuit. It requires
no external components to serve its protective function.
VCC OVP and generate VCC
For the CM6805A/CM6806A system, if VCC is generated
from a source that is proportional to the PFC output voltage
and once that source reaches 17.9V, PFCOUT, PFC driver
will be off.
The VCC OVP resets once the VCC discharges below
16.4V, PFC output driver is enabled. It serves as redundant
PFC OVP function.
Typically, there is a bootstrap winding off the boost inductor.
The VCC OVP comparator senses when this voltage
exceeds 17.9V, and terminates the PFC output drive. Once
the VCC rail has decreased to below 16.4V the PFC output
drive be enabled. Given that 16V on VCC corresponds to
380V on the PFC output, 17.9V on VCC corresponds to an
OVP level of 460V.
It is a necessary to put RC filter between bootstrap winding
and VCC. For VCC=15V, it is sufficient to drive either a
power MOSFET or a IGBT.
Champion Microelectronic Corporation
Page 14
CM6805(A;B;C)/CM6806(A;B;C)
(ABC0401A03A/03C/05A ; ABC0401A06A/01B)
10-PIN Green-Mode PFC/PWM Combo CONTROLLER for High Density AC Adapter
UVLO
The UVLO threshold is 13V providing 3V hysteresis.
PFCOUT and PWMOUT
Both PFCOUT and PWMOUT are CMOS drivers. They both
have adaptive anti-shoot through to reduce the switching
loss. Its pull-up is a 30ohm PMOS driver and its pull-down
is a 15ohm NMOS driver. It can source 0.5A and sink 1A if
the VCC is above 15V.
PWM Section
Green Mode
CM6805A/CM6806A has the green mode function to
improve the light load efficiency. PWM Green Mode will
happen when the PWMCMP (PWM Comparator) Duty
Cycle is less than ~ 6%, in the next cycle, the PWMOUT
pulse will be removed until PWMCMP Duty Cycle is greater
than 6%, then the next cycle, PWMOUT pulse appears.
In other words, during the green mode, PWM switching
frequency will reduce to improve the efficiency. With the
proper external components, CM6805A/CM6806A can
easily meet energy star and blue angel specification.
After 10mS digital soft start, CM6805A/CM6806A’s PWM is
operating as a typical current mode. It requires a secondary
feedback, typically, it is configured with CM431, and photo
couple.
At normal operation, the threshold voltage of the V + I pin is
1.5V. When the V + I is greater than 1.5V, PWM output driver
will turn off the PWM Power MOSfet.
When the Soft Start is triggered, the V+I threshold is around
150mV.
Soft Start Can be triggered by the following conditions:
1.) During the startup (VCC is less than 10V)
2.) DC to DC short (PWMtrifault is greater than VCC-0.7V)
During above 3 conditions, the V + I threshold is around
150mV until the conditions have been removed.
After above 3 conditions have been removed, the internal
Soft Start D to A will ramp up the voltage from ~150mV to
2V. Each Soft Start Ramp can last around 10mS.
Short (PWMtrifault)
When PWMtrifault is greater VCC-0.7V, PWMOUT will be
turned off. It can be used to detected the following 2 things:
1.) Short Protection
2.) Thermal Shut Down
To achieve above item, it requires a negative temperature
coefficient Resistor.
The following figure shows the typical circuit for PWMtrifault
and V + I pins.
Turn off PFC(PWMtrifault)
Since PWM Section is different from CM6800 family, it
needs the emitter of the photo couple to connected with V +
I instead of the collector. The PWM current information also
goes into V + I. Usually, the PWM current information
requires a RC filter before goes into the V + I.
Therefore, V + I actually is a summing node from voltage
information which is from photo couple and CM431 and
current information which is from one end of PWM sensing
resistor and the signal goes through a single pole, RC filter
then enter the V + I pin.
This RC filter at DCILMIT also serves several functions:
1.) It protects IC.
2.) It provides level shift for voltage information.
3.) It filters the switching noise from current
information.
2005/12/28
Preliminary
When
PWMtrifault
is
less
than
(VCC-1.4V)/2,
CM6805A/CM6806A will turn off PFC. Usually; it means load
has been reduced to a level, which is the level of the Green
Mode threshold. Usually, we set the Green Mode threshold
around 20% of the full load.
After turning off PFC, the efficiency will be increased due to
the input voltage is higher and less switching events.
Component Reduction
Components associated with the VRMS and IEAO pins of a
typical PFC controller such as the CM6800 have been
eliminated. The PFC power limit and bandwidth does vary
with line voltage.
Champion Microelectronic Corporation
Page 15
CM6805(A;B;C)/CM6806(A;B;C)
(ABC0401A03A/03C/05A ; ABC0401A06A/01B)
10-PIN Green-Mode PFC/PWM Combo CONTROLLER for High Density AC Adapter
2005/12/28
Preliminary
Champion Microelectronic Corporation
Page 16
CM6805(A;B;C)/CM6806(A;B;C)
(ABC0401A03A/03C/05A ; ABC0401A06A/01B)
10-PIN Green-Mode PFC/PWM Combo CONTROLLER for High Density AC Adapter
PACKAGE DIMENSION
10 Pin-SSOP (R10)
PIN 1 ID
θ
B
F
ZD
θ
2005/12/28
Preliminary
Champion Microelectronic Corporation
Page 17
CM6805(A;B;C)/CM6806(A;B;C)
(ABC0401A03A/03C/05A ; ABC0401A06A/01B)
10-PIN Green-Mode PFC/PWM Combo CONTROLLER for High Density AC Adapter
NUMBERING SCHEME
Ordering Number: CM6805AXY (note1)
Ordering Number: CM6805AGXY (note2)
note1:
X : Suffix for Temperature Range (note 3)
Y : Suffix for Package Type (note 4)
note2:
G : Suffix for Pb Free Product
X : Suffix for Temperature Range (note 3)
Y : Suffix for Package Type (note 4)
note 3:
X= I : -40℃~+125℃
note 4:
R: SSOP-10
2005/12/28
Preliminary
Champion Microelectronic Corporation
Page 18
CM6805(A;B;C)/CM6806(A;B;C)
(ABC0401A03A/03C/05A ; ABC0401A06A/01B)
10-PIN Green-Mode PFC/PWM Combo CONTROLLER for High Density AC Adapter
IMPORTANT NOTICE
Champion Microelectronic Corporation (CMC) reserves the right to make changes to its products or to discontinue any integrated
circuit product or service without notice, and advises its customers to obtain the latest version of relevant information to verify,
before placing orders, that the information being relied on is current.
A few applications using integrated circuit products may involve potential risks of death, personal injury, or severe property or
environmental damage. CMC integrated circuit products are not designed, intended, authorized, or warranted to be suitable for
use in life-support applications, devices or systems or other critical applications. Use of CMC products in such applications is
understood to be fully at the risk of the customer. In order to minimize risks associated with the customer’s applications, the
customer should provide adequate design and operating safeguards.
HsinChu Headquarter
Sales & Marketing
5F, No. 11, Park Avenue II,
Science-Based Industrial Park,
HsinChu City, Taiwan
11F, No. 306-3, Sec. 1, Ta Tung Rd.,
Hsichih, Taipei Hsien 221
Taiwan, R.O.C.
T E L : +886-3-567 9979
F A X : +886-3-567 9909
http://www.champion-micro.com
T E L : +886-2-8692 1591
F A X : +886-2-8692 1596
2005/12/28
Preliminary
Champion Microelectronic Corporation
Page 19