General
Description
The CM6824 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-1000-2-3 specifications.
Intended as a BiCMOS version of the industry-standard ML4824, CM6824
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.
---------------------------------------------------------------------------------------------------------------------------------------------
Features
- Pin to pin compatible
with ML4824 and FAN6824
- Additional folded-back
current limit for PWM section
- 23V Bi-CMOS processu 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
(100ŁgA 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
---------------------------------------------------------------------------------------------------------------------------------------------
Packages
- CM6824IP:
16-PIN PDIP (P16)
- CM6824IS:
16-PIN Wide SOP (S16)
