CM6900

Features:

` Patent Filed #5,565,761, #5,747,977, #5,742,151, #5,804,950, #5,798,635
` Inrush Current Control
` Separated PFC OVP pin
` Separated Power VCCA and Analog VCCA
` Separated Power Ground and Analog Ground
` Additional folded-back current limit for PWM section.
` 23V Bi-CMOS process
` 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 (100A 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
` VCCA OVP Comparator
` Low Power Detect Comparator
` 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


Application

· 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


Pinout




Specifications

Parameter	Min.	Max.	Units
VCC MAX		23	V
IEAO	0	4.5	V
ISENSE Voltage	-5	0.7	V
PFC OUT	GND 0.3	VCCA + 0.3	V
PWM OUT	GND 0.3	VCCA + 0.3	V
INRUSHSTOPB	GND 0.3	VCCA + 0.3	V
Voltage on Any Other Pin	GND 0.3	VREF + 0.3	V
IREF		10	mA
IAC Input Current		1	mA
Peak PFC OUT Current, Source or Sink		1	A
Peak PWM OUT Current, Source or Sink		1	A
PFC OUT, PWM OUT Energy Per Cycle		1.5	J
Junction Temperature		150
Storage Temperature Range	-65	150
Operating Temperature Range	-40	125
Lead Temperature (Soldering, 10 sec)		260
Thermal Resistance (JA) Plastic DIP Plastic SOIC		80 105	/W /W

Description

The CM6900 is a controller for power factor corrected, switched mode power suppliers. 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 ML4824, CM6900 includes circuits for the implementation of leading edge, average current, "boost" type power factor correction and a trailing edge, pulse width modulator (PWM). The CM6900 has additional features besides all the features of CM6800. Additional features are Inrush Current Control, Separated PFC OVP pin, Separated Power VCCA pin and Analog VCCA pin, and Separated Power Ground pin and Analog Ground pin. Gate-driver with 1A capabilities minimizes the need for external driver circuits. Low power requirements improve efficiency and reduce component costs.
An over-voltage comparator CM6900 shuts down the PFC section in  the event of a sudden decrease in load. The PFC section also includes peak current limiting and input voltage brownout protection. The PWM section can be operated in current or voltage mode, at up to 250kHz, and includes an accurate 50% duty cycle limit to prevent transformer saturation.