10-PIN Green-Mode PFC/PWM Combo CONTROLLER for LCD Standby Power
The CM6803A is the Green-Mode PFC/PWM Combo
controller for Standby in LCD power. For the LCD power
supply, its input current shaping PFC performance could be
very close to the performance of the CM6800 or ML4800
leading edge modulation average current topology.
CM6803A 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 CM6803A /
CM6808A includes circuits for the implementation of a
leading edge, input current shaping technique “boost” type
PFC and a trailing edge, PWM.
The CM6803A’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.
The PWM has the Green Mode Functions.
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.
PFC has a smart I/O pin which can sense the remote on/off
signal and generate a high level voltage to turn on the
Patent Filed #5,565,761, #5,747,977, #5,742,151,
The PWM has the Green Mode to meet blue angel and
energy star spec.
10-Pin SOIC package
PWM pulse skipping for the green mode
Use RAC as the Startup resistor which can be > 2000K or
higher at IAC pin
It can use the HV bipolar to start up the chip and it helps
Easy to configure into Boost Follower
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
Feedforward IAC pin to do the automatic slope
PFCOVP, VCCOVP, Precision -1V PFC ILIMIT, PFC
Tri-Fault Detect comparator to meet UL1950
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
High efficiency trailing-edge current mode PWM
Exact 50% PWM maximum duty cycle
UVLO, REFOK, and brownout protection
Digital PFC and PWM soft start, ~10mS
Precision PWM 1.5V current limit for current mode
Smart I/O to sense remote on/off signal and Turn on PFC
Smart I/O also can be generated a high level voltage for the
next power stage turn on signal.
Champion Microelectronic Corporation