©2001 Fairchild Semiconductor Corporation
www.fairchildsemi.com
Rev.1.0.1
Features
• Quasi Resonant Converter Controller
• Internal Burst Mode Controller for Stand-by Mode
• Pulse by Pulse Current Limiting
• Over Current Latch Protection
• Over Voltage Protection ( Vsync: Min. 11V )
• Internal Thermal Shutdown Function
• Unde r Voltage Lo ck out
• Internal High Voltage Sense FET
• Auto- Re st art Mo de
Description
The Fairchild Power Swit ch(FPS) product family is speci ally
designed for an off-line SMPS with minimal external
components. The Fairchild Power Switch(FPS) consists of a
high voltage power SenseFET and a current mode PWM IC.
The integrated PWM controller includes the fixed oscillator,
the under voltage lock out, the leading edge blanking, the
optimized gate turn-on/turn-of f driver, the thermal shut down
protection, the over voltage protection, and the temperature
compensated precision current sources for loop compensation
and fault protection circuitry. Compared to a discrete
MOSFET and a controller or a RCC switching converter
solutions, a F airchild Power Switch(F PS) can reduce the total
number of components, design size, and weight, so it will
improve ef ficiency, productivity, and system reliabilit y. It has
a basic platform well suited for cost-effective design in a
quasi-resonant converter as a C-TV power supply.
TO-220F-5L
1. Drain 2. GND 3. VCC
4. Feedback 5. Sync
Internal Block Diagram
OSC
OVP
LEB
S _
Q
R
Delay
Vref
Internal
Bias
1
3
5
4
TSD
150 Power-on
Reset
S
Q
R
Burs t mode
controller
Ifb
Ids
Vds
REF.
PSR
REF.
Sync.
REF.
Ron
Roff
Rsense
Vfb offset
OCL
REF.
PWM
UVLO
2
Drain
GND
VCC
Feedbock
Sync
KA5Q0740RT
Fairchild Power Switch(FPS )