©2005 Fairchild Semiconductor Corporation
www.fairchildsemi.com
Rev.1.1.0
Features
• Internal Avalanche Rugged SenseFET
• Low Start-up Current (max 40uA)
• Low Power Consumption under 1 W at 240VAC and
0.4W Load
• Precise Fixed Operating Frequency (66kHz)
• Frequency Modulation for low EMI
• Pulse by Pulse Current Limiting (Adjustable)
• Over Voltage Protection (OVP)
• Over Load Protection (OLP)
• Thermal Shutdown Function (TSD)
• Auto-Restart Mode
• Under Voltage Lock Out (UVLO) with Hysteresis
• Built-in Soft Start (15ms)
Application
• SMPS for VCR, SVR, STB, DVD and DVCD
• Adaptor
• SMPS for LCD Monitor
Related Application Notes
• AN-4137: Design Guidelines for Off-line Flyback
Converters Using Fairchild Power Switch (FPS)
• AN-4140
: Transformer Design Consideration for off-line
Flyback Converters using Fairchild Power Switch
• AN-4141
: Troubleshooting and Design Tips for Fairchild
Power Switch Flyback Applications
• AN-4148
: Audible Noise Reduction Techniques for FPS
Applications
Description
The FSCM0765R is an integrated Pulse Width Modulator
(PWM) and SenseFET specifically designed for high
performance offline Switch Mode Power Supplies (SMPS)
with minimal external components. This device is an
integrated high voltage power switching regulator which
combines
an avalanche rugged SenseFET with a current
mode PWM control block. The PWM controller includes
integrated fixed frequency oscillator, under voltage lockout,
leading edge blanking (LEB), optimized gate driver, internal
soft start, temperature compensated precise current sources
for a loop compensation, and self protection circuitry.
Compared with a discrete MOSFET and PWM controller
solution, it can reduce total cost, component count, size
, and
weight while simultaneously increasing efficiency, productivity,
and system reliability. This device is a basic platform well
suited for cost effective designs of flyback converters.
Table 1. Maximum Output Power
Notes:
1. Typical continuous power in a non-ventilated enclosed
adapter measured at 50°C ambient.
2. Maximum practical continuous power in an open-frame
design at 50°C ambient.
3. 230 VAC or 100/115 VAC with doubler.
Typical Circuit
Figure 1. Typical Flyback Application
OUTPUT POWER TABLE
PRODUCT
230VAC ±15%
(3)
85-265VAC
Adapt-
er
(1)
Open
Frame
(2)
Adapt-
er
(1)
Open
Frame
(2)
FSCM0565RJ 50W 65W 40W 50W
FSCM0765RJ 65W 70W 50W 60W
FSCM0565RI 50W 65W 40W 50W
FSCM0765RI 65W 70W 50W 60W
FSCM0565RG 70W 85W 60W 70W
FSCM0765RG 85W 95W 70W 85W
Drain
GNDVfb Vcc
PWM
AC
IN
DC
OUT
I
limit
FSCM0765R
Green Mode Fairchild Power Switch (FPS
TM
)
