
CM6503/4
8-PIN S
INGLE
PFC C
ONTROLLER
W
ITH 50%
PWM
C
LOCK
S
IGNAL
GENERAL DESCRIPTION
The 8 pin single PFC controller with 50% PWM clock ,
CM6503/4 is a space-saving 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 performance could be very close to
CM6800 or ML4800 architecture. Its IAC has dual function.
8 pin CM6503/4 does not require and bleed resistors. It use
IAC pin during the start up condition to start up CM6503/4.
After CM6503/4 is on, IAC will switch itself back to the IAC
function.
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
CM6503/4 includes circuits for the implementation of a
leading edge, average current “boost” type PFC and a
trailing edge, PWM Clock signal which will not turn on until
PFC boost output reaches steady state.
The CM6503’s PFC and PWM Clock operate at the same
frequency, 67kHz. The PFC frequency of the CM6504 is
automatically set at half that of the 134kHz PWM. This
higher frequency allows the user to design with smaller
PWM components while maintaining the optimum operating
frequency for the PFC. An 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.
APPLICATIONS
2002/07/16
Preliminary
Rev. 0.2
Champion Microelectronic Corporation
Page 1
FEATURES
!
Enable lowest BOM for power supply with PFC
!
Patented slew rate enhanced voltage error amplifier with
advanced input current shaping technique
!
Universal Line Input Voltage
!
No bleed resistor required
!
CCM boost or DCM boost with leading edge modulation
PFC using Input Current Shaping Technique
!
Feedforward IAC pin to do the automatic slope
compensation
!
PFCOVP, TriFault Detect, PFC VCCOVP, Precision -1V
PFC ILIMIT
!
Low supply currents; start-up: 100uA typical, operating
current: 2mA typical.
!
Synchronized leading PFC and trailing edge modulation
PWM Clock for the down stream DC to DC stage 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 Clock
when PFC reach steady state
!
UVLO, VREFOK, and brownout protection
24 Hours Technical Support---WebSIM
Champion provides customers an online circuit simulation tool
called WebSIM. You could simply logon our website at
www.champion-micro.com for details.
PIN CONFIGURATION
!
Desktop PC Power Supply
!
AC Adaptor
!
Internet Server Power Supply
!
IPC Power Supply
!
UPS
!
Battery Charger
!
DC Motor Power Supply
!
Monitor Power Supply
!
Telecom System Power Supply
!
Distributed Power
DIP-08 (P08)
Top View
1
2
3
4
8
7
6
5
PFCOUT
GND
ISENSE
VEAO
PWMCLK
VCC
IAC
V
FB