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FSDM311
Features
Green Mode Fairchild Power Switch (FPS
TM
)
• Internal Avalanche Rugged Sense FET
• Precision Fixed Operating Frequency (67kHz)
• Advanced Burst-Mode operation Consumes under 0.2W
at 265Vac and no load
• Internal Start-up Switch and Soft Start
• Under Voltage Lock Out (UVLO) with Hysteresis
• Pulse by Pulse Current Limit
• Over Load Protection (OLP)
• Over Voltage Protection (OVP)
• Internal Thermal Shutdown Function (TSD)
• Secondary Side Regulation
• Auto-Restart Mode
TYPICAL POWER CAPABILITY
PRODUCT
FSDM311
FSDM311L
Open Frame
230VAC
±15%
(1)
20W
20W
85-265VAC
12W
12W
Table 1. Notes: 1. 230 VAC or 100/115 VAC with doubler.
Typical Circuit
Applications
• Charger & Adaptor for Mobile Phone, PDA & MP3
• Auxiliary Power for White Goods, PC, C-TV & Monitor
AC
IN
DC
OUT
Vstr
Drain
Description
The FSDM311 is an integrated Pulse Width Modulator
(PWM) and Sense FET specially designed for high perfor-
mance off-line Switch Mode Power Supplies (SMPS) with
minimal external components. This device is a monolithic
high voltage power switching regulator which combines an
VDMOS Sense FET with a voltage mode PWM control
block. The integrated PWM controller features include: a
fixed oscillator, Under Voltage Lock Out (UVLO) protec-
tion, Leading Edge Blanking (LEB), optimized gate turn-on/
turn-off driver, thermal shut down protection (TSD), temper-
ature compensated precision current sources for loop com-
pensation and fault protection circuitry. When compared to a
discrete MOSFET and controller or RCC switching con-
verter solution, the FSDM311 reduces total component
count, design size, weight and at the same time increases
efficiency, productivity, and system reliability. This device is
a basic platform well suited for cost effective designs of fly-
back converters.
Vfb
PWM
Vcc
Source
Figure 1. Typical Flyback Application using FSDM311
Rev.1.0.5
©2004 Fairchild Semiconductor Corporation
FAIRCHILD [ FAIRCHILD SEMICONDUCTOR ]
