CM6802SAG

GENERAL DESCRIPTION

The CM6802 is a green PFC/PWM. It is the new generation of ML4802, ML4841, ML4801 and ML4824-2. Its system clock frequency is generated by the external RT and CT, and then its PWM frequency is 50% of the clock and its PFC frequency is 25% of the clock. CM6802 is designed to
be pin-pin compatible with CM6800 family, ML4800 family and ML4824 family. Its PWM (DC to DC section) can be easily configured to Voltage Mode or Current Mode. The green mode function can easily be designed so during the no load condition, its input power can be less than 0.75Watt
without shutting off PFC. Its PFC green mode threshold and the PWM green mode threshold can separately set by selecting the proper the RC filter at ISENSE pin (pin3) and CT on RAMP 1 pin (pin 7). Power Factor Correction (PFC) allows the use of smaller, lower cost bulk capacitors,
reduces power line loading and stress on the switching FETs, and results in a power supply that fully compiles with IEC-1000-3-2 specifications. Intended as a BiCMOS version of the industry-standard CM6800, CM6802 includes circuits for the implementation of leading edge, average
current, “boost” type power factor correction and a trailing edge, pulse width modulator (PWM). Both PFC and PWM Gate-driver with 0.5A capabilities minimizes the need for external driver circuits. Low power requirements improve efficiency and reduce component costs.

FEATURES

Patent Number #5,565,761, #5,747,977, #5,742,151, #5,804,950, #5,798,635
fosc=2 x fpwm =4 x fpfc
No bleed resistor required
Before the chip wakes up, IAC can start up VCC
Pin to pin Compatible with CM6800, ML4824 and ML4800 (It needs to modify the values of the external component to work properly).
User Program PFC automatic green mode threshold(patented)
User Program PWM automatic green mode threshold(patented)
Input power less than 0.75Watt without shutting off PFC at no load condition.
Additional folded-back current limit for PWM section.
23V Bi-CMOS process
PWM pulse keeping for the green mode
VIN OK guaranteed turn on PWM at 2.5V instead of 1.5V
Internally synchronized leading edge PFC and trailing edge PWM in one IC
Slew rate enhanced transconductance error amplifier for ultra-fast PFC response
Low start-up current (30µA typ.)
Low operating current (3.0mA type.)
Low total harmonic distortion, high PF
Reduces ripple current in the storage capacitor between the PFC and PWM sections
Average current, continuous or discontinuous boost leading edge PFC
VCC OVP Comparator will turn off both PFC and PWM
Low Power Detect Comparator
Tri-Fault detect to meet UL1950
PWM configurable for current mode or voltage mode operation
Current fed gain modulator for improved noise immunity
Brown-out control, over-voltage protection, UVLO, and soft start, and Reference OK

APPLICATIONS

Desktop PC Power Supply
Internet Server Power Supply
IPC Power Supply
UPS
Battery Charger
DC Motor Power Supply
Monitor Power Supply
Telecom System Power Supply
Distributed Power