CM6903A
Low Pin Count PFC/PWM C
ONTROLLER
C
OMBO
GENERAL DESCRIPTION
The CM6903A is a space-saving PFC-PWM controller
for power factor corrected, switched mode power supplies
that offers very low start-up and operating currents. For the
power supply less than 500Watt, its input current shaping
PFC performance could be very close to CM6800 or
ML4800 architecture.
Power Factor Correction (PFC) offers the use of
smaller, lower cost bulk capacitors, reduces power line
loading and stress on the switching FETs, and results in a
power supply fully compliant to IEC1000-3-2 specifications.
The CM6903A includes circuits for the implementation of a
leading edge, input current shaping technique “boost” type
PFC and a trailing edge, PWM.
The CM6903A’s PFC and PWM operate at the same
frequency, 67.5kHz. A PFC OVP comparator shuts down
the PFC section in the event of a sudden decrease in load.
The PFC section also includes peak current limiting for
enhanced system reliability.
FEATURES
Patent
Number
#5,565,761,
#5,747,977,
#5,742,151,
#5,804,950, #5,798,635
Pin to pin compatible with FAN6903/4
Enable lowest BOM for power supply with PFC
Internally synchronized PFC and PWM in one IC
Patented slew rate enhanced voltage error amplifier with
advanced input current shaping technique
Universal Line Input Voltage
CCM boost or DCM boost with leading edge modulation
PFC using Input Current Shaping Technique
Feed forward IAC pin to do the automatic slope
compensation
PFCOVP, PFC VCCOVP, Precision -1V PFC ILIMIT,
Tri-Fault Detect comparator to meet UL1950
No bleed resistor required
Low supply currents; start-up: 100uA typical, operating
current: 2mA typical.
Synchronized leading PFC and trailing edge modulation
PWM to reduce ripple current in the storage capacitor
between the PFC and PWM sections and to reduce
switching noise in the system
VINOK Comparator to guarantee to enable PWM when
PFC reach steady state
High efficiency trailing-edge current mode PWM
UVLO, REFOK, and brownout protection
Digital PWM softstart: CM6903A (10ms)
Precision PWM 1.5V current limit for current mode
operation
APPLICATIONS
Desktop PC
AC Adaptor
Open Frame
PIN CONFIGURATION
SIP-09 (Z09)
Front View
DC ILIMIT
PW MOUT
PFCOUT
ISENSE
VEAO
GND
VCC
VFB
1
2
3
4
5
6
7
8
2008/10/20 Rev1.4
Champion Microelectronic Corporation
IAC
9
Page 1
CM6903A
Low Pin Count PFC/PWM C
ONTROLLER
C
OMBO
PIN DESCRIPTION
Operating Voltage
Pin No.
Symbol
Description
Min.
1
2
3
4
5
6
7
8
9
DC I
LIMIT
V
CC
PWM OUT
PFC OUT
GND
I
SENSE
VEAO
V
FB
IAC
PWM current limit comparator input
Positive supply
PWM driver output
PFC driver output
Ground
Current sense input to the PFC current limit comparator
PFC transconductance voltage error amplifier output
PFC transconductance voltage error amplifier input
Feedforward input to do slope compensation and to start up
the system
-5
0
0
0
2.5
0.7
6
3
1
V
V
V
V
0
10
0
0
13
Typ.
Max.
1.5
18
VCC
VCC
Unit
V
V
V
V
ORDERING INFORMATION
Initial Accuracy (KHz)
Part Number
Operation Frequency
Min
CM6903AIZ
CM6903AGIZ*
CM6903AXIZ*
Fpwm = Fpfc = 67.5Khz
Fpwm = Fpfc = 67.5Khz
Fpwm = Fpfc = 67.5Khz
60
60
60
Typ
67.5
67.5
67.5
Max
74
74
74
-40℃ to 125℃
-40℃ to 125℃
-40℃ to 125℃
9-Pin SIP (Z09)
9-Pin SIP (Z09)
9-Pin SIP (Z09)
Temperature Range
Package
Note:
1.G : Suffix for Pb Free Product
2.Initial Accuracy : T
A
=25℃
3.X : Suffix for Halogen Free Product
2008/10/20 Rev1.4
Champion Microelectronic Corporation
Page 2
CM6903A
Low Pin Count PFC/PWM C
ONTROLLER
C
OMBO
BLOCK DIAGRAM
9
IAC
VREFOK
1
1
R1B
400K
-
1
R1A
100K
2
-
R1C
5.1K
2
2
7
VEAO
VCC
2
6
ISENSE
PFC CMP
.
8
VFB
-
2.5V
VCC
17.9V
16.4V
0.5V
2.75V
2.5V
-1V
ABSOLUTE MAXIMUM RATINGS
Absolute Maximum ratings are those values beyond which the device could be permanently damaged.
Parameter
V
CC
MAX
IAC (after start up)
I
SENSE
Voltage
PFC OUT
PWM OUT
VEAO
Voltage on Any Other Pin
I
CC
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 (θ
JA
)
-65
-40
GND-0.3
-5
GND – 0.3
GND – 0.3
0
GND – 0.3
Min.
Max.
20
1.0
0.7
VCC + 0.3
VCC + 0.3
6.3
VCC + 0.3
40
0.5
0.5
1.5
150
150
125
260
80
Units
V
V
V
V
V
V
V
mA
A
A
μJ
℃
℃
℃
℃
℃/W
2008/10/20 Rev1.4
+
ISENSEAMP
+
S
R
Q
VREF OK
Q
4
PFCOUT
gmv
.
.
OR
RAMP
.
+
FAULTB
UVLO
VCC OVP
+
-
-
.
VCC
.
.
UVLO
PFCCLKB
PFCCLKB
.
-
Tri-Fault Detect
.
PW
MCLK
PWMCLK
.
3
VREF OK
VFB
2.45V
0.75V
-
+
+
+
VIN OK
.
OS
R
R
R
Q
PWMOUT
Q
+
-
-
PFC OVP
.
1.5V
-
-
+
.
PWM CMP
10ms
-
PFC ILIMIT
.
.
PWM CLK
.
+
SS
CM6903A
fpfc= 67.5KHz
fpwm= 67.5KHz
1
DCILIMIT
GND
5
Champion Microelectronic Corporation
Page 3
CM6903A
Low Pin Count PFC/PWM C
ONTROLLER
C
OMBO
ELECTRICAL CHARACTERISTICS
T
A
=Operating Temperature Range (Note 1)
CM6903A
Min.
0
V
NONINV
= V
INV
, VEAO = 3.75V
Note 2
5.8
V
FB
= 3V, VEAO = 6V
V
FB
= 1.5V, VEAO = 1.5V
11V < V
CC
< 16.5V
IAC
Input Impedance
Threshold Voltage
Hysteresis
PFC OVP Comparator
Threshold Voltage
Hysteresis
PFC I
LIMIT
Comparator
Threshold Voltage
Delay to Output
V
IN
OK Comparator
Threshold Voltage
Hysteresis
PWM Digital Soft Start
Digital Soft Start Timer (Note 2)
Threshold Voltage
Delay to Output (Note 2)
Tri-Fault Detect Comparator
Fault Detect HIGH
Time to Fault Detect HIGH
Fault Detect LOW
Initial Accuracy
Voltage Stability
Temperature Stability
Total Variation
PFC Dead Time (Note 2)
Line, Temp
60
0.3
Oscillator
T
A
= 25℃
10V < V
CC
< 15V
V
FB
=V
FAULT DETECT LOW
to V
FB
= OPEN,
470pF from V
FB
to GND
0.4
62
2.65
2.75
2
0.5
67
1
2
67
0.45
74.5
0.65
2.85
4
0.6
74
V
ms
V
kHz
%
%
kHz
μs
Right After Start Up (CM6903A)
DC I
LIMIT
Comparator
1.4
1.5
150
1.6
300
V
ns
10
ms
2.35
1.65
2.45
1.75
2.55
1.85
V
V
-0.9
-1
150
-1.15
300
V
ns
2.60
200
2.77
2.85
290
V
mV
ISENSE = 0V
VCC OVP Comparator
17.4
1.2
17.9
1.5
18.4
1.65
V
V
4080
5100
6120
Ohm
-20
30
50
50
30
2.45
65
2.5
-0.5
6.0
0.1
-35
40
60
60
0.4
Typ.
Max.
5
90
2.55
-1.0
Unless otherwise stated, these specifications apply Vcc=+15V,
Symbol
Parameter
Test Conditions
Voltage Error Amplifier (g
mv
)
Unit
Input Voltage Range
Transconductance
Feedback Reference Voltage
Input Bias Current
Output High Voltage
Output Low Voltage
Sink Current
Source Current
Open Loop Gain
Power Supply Rejection Ratio
V
μmho
V
μA
V
V
μA
μA
dB
dB
2008/10/20 Rev1.4
Champion Microelectronic Corporation
Page 4
CM6903A
Low Pin Count PFC/PWM C
ONTROLLER
C
OMBO
ELECTRICAL CHARACTERISTICS
(Conti.) Unless otherwise stated, these specifications apply
Vcc=+15V, T
A
=Operating Temperature Range (Note 1)
CM6903A
Symbol
Parameter
Test Conditions
Min.
PFC
Minimum Duty Cycle
Maximum Duty Cycle
Output Low Impedance
Output Low Voltage
Output High Impendence
Output High Voltage
Rise/Fall Time (Note 2)
I
OUT
= 100mA, V
CC
= 15V
C
L
= 1000pF
PWM
Duty Cycle Range
Output Low Impedance
Output Low Voltage
Output High Impendence
Output High Voltage
Rise/Fall Time (Note 2)
I
OUT
= 100mA, V
CC
= 15V
C
L
= 1000pF
Supply
Start-Up Current
Operating Current
Undervoltage Lockout Threshold
Undervoltage Lockout Hysteresis
V
CC
= 11V, C
L
= 0
V
CC
= 15V, C
L
= 0
12.74
2.85
100
2.5
13.0
3.0
150
4.0
13.26
3.15
uA
mA
V
V
13.5
I
OUT
= -100mA
I
OUT
= -10mA, V
CC
= 8V
CM6903A
0-49.5
15
0.8
0.7
30
14.2
50
0-50
22.5
1.5
1.5
45
%
ohm
V
V
ohm
V
ns
13.5
I
OUT
= -100mA
I
OUT
= -10mA, V
CC
= 8V
I
AC
=100uA,V
FB
=2.55V, I
SENSE
= 0V
I
AC
=0uA,V
FB
=2.0V, I
SENSE
= 0V
90
95
15
0.8
0.4
30
14.2
50
22.5
1.5
0.8
45
0
%
%
ohm
V
V
ohm
V
ns
Typ.
Max.
Unit
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.
2008/10/20 Rev1.4
Champion Microelectronic Corporation
Page 5