CM6903A Datasheet, PDF (2/14 Pages) Champion Microelectronic Corp. – Low Pin Count PFC/PWM CONTROLLER COMBO

CM6903A
Low Pin Count PFC/PWM CONTROLLER COMBO
PIN DESCRIPTION
Pin No. Symbol
Description
1
DC I_LIMIT
PWM current limit comparator input
Operating Voltage
Min.
Typ.
Max. Unit
0
1.5
V
2
V_CC
Positive supply
10
13
18
V
3 PWM OUT PWM driver output
0
VCC
V
4 PFC OUT PFC driver output
0
VCC
V
5 GND
Ground
6
I_SENSE
Current sense input to the PFC current limit comparator
-5
7 VEAO
PFC transconductance voltage error amplifier output
0
0.7
V
6
V
8
V_FB
PFC transconductance voltage error amplifier input
0
2.5
3
V
9 IAC
Feedforward input to do slope compensation and to start up
0
the system
1
V
BLOCK DIAGRAM
ISENSE
6
R1A
100K ohm
VFB
8
7
VEAO
R1C
9
IAC
VREFOK
5.1K ohm
R1B
400K ohm
+
U1
+
.
ISENSEAMP
SUM
OUT
.
2.5V
gmv
-
.
+
VCC
17.9V
16.4V
0.5V
2.75V
2.5V
-1V
VCC OVP
+
.
-
-
Tri-Fault
Detect
-
.
+
PFC OVP
+
.
-
-
-
.
+
PFC ILIMIT
2
VCC
RAMP
.
.
-
.
+
PFCCMP
FAULTB
S
Q
R
R
Q
UVLO
VREF OK
VCC
.
.
UVLO
OSC
PFCCLKB
.
PWMCLK
.
VFB
2.45V
0.75V
VIN OK
-
.
+
+
PWM CLK
1.5V
10mS
.
.
1V
.
SS
-
-
.
+
PWMCMP
PFCCLKB
PWMCLK
S
Q
R
R
R
Q
VREF OK
CM6903A
fpfc= 67KHz
fpwm=67KHz
1
DCILIMIT
5
GND
4
PFCOUT
3
PWMOUT
2005/01/20
Champion Microelectronic Corporation
Page 2