CM6800A_09 Datasheet, PDF (1/18 Pages) Champion Microelectronic Corp. – LOW START-UP CURRENT PFC/PWM CONTROLLER COMBO

CM6800A
LOW START-UP CURRENT PFC/PWM CONTROLLER COMBO
GENERAL DESCRIPTION
FEATURES
The CM6800A 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, CM6800A ‹
includes circuits for the implementation of leading edge,
average current, “boost” type power factor correction and a ‹
trailing edge, pulse width modulator (PWM). 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 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.
‹
‹
CM6800A includes an additional folded-back current limit
for PWM section to provide short circuit protection function.
Patent Number #5,565,761, #5,747,977, #5,742,151,
#5,804,950, #5,798,635
Pin to pin compatible with ML4800 and FAN4800
Additional folded-back current limit for PWM section.
23V Bi-CMOS process
VIN OK turn on PWM at 2.25V instead of 1.5V(ML4800).
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 (100 μ A 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, 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
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
PIN CONFIGURATION
SOP-16 (S16) / PDIP-16 (P16)
Top View
1
IEAO
VEAO
16
2
IAC
VFB
15
3
ISENSE
VREF
14
4
VRMS
VCC
13
5
SS
PFC OUT
12
6
VDC
PWM OUT
11
7
RAMP1
GND
10
8
RAMP2
DC ILIMIT
9
2009/08/10 Rev. 1.6
Champion Microelectronic Corporation
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