DH321 DIP IC

Features
? Internal Avalanche Rugged Sense FET
? Consumes only 0.65W at 240VAC & 0.3W load with
Advanced Burst-Mode Operation
? Frequency Modulation for EMI Reduction
? Precision Fixed Operating Frequency
? Internal Start-up Circuit
? Pulse-by-Pulse Current Limiting
? Abnormal Over Current Protection (AOCP)
? Over Voltage Protection (OVP)
? Over Load Protection (OLP)
? Internal Thermal Shutdown Function (TSD)
? Auto-Restart Mode
? Under Voltage Lockout (UVLO)
? Low Operating Current (max 3mA)
? Adjustable Peak Current Limit
? Built-in Soft Start
Applications
? SMPS for STB, Low cost DVD Player
? Auxiliary Power for PC
? Adapter & Charger
Related Application Notes
? AN-4137, 4141, 4147(Flyback) / AN-4134(Forward)
Description
Each product in the FSDx321 (x for H, L) family consists of
an integrated Pulse Width Modulator (PWM) and Sense
FET, and is specifically designed for high performance offline Switch Mode Power Supplies (SMPS) with minimal
external components. Both devices are integrated high voltage power switching regulators which combine an avalanche
rugged Sense FET with a current mode PWM control block.
The integrated PWM controller features include: a fixed
oscillator with frequency modulation for reduced EMI,
Under Voltage Lock Out (UVLO) protection, Leading Edge
Blanking (LEB), an optimized gate turn-on/turn-off driver,
Thermal Shut Down (TSD) protection, Abnormal Over Current Protection (AOCP) and temperature compensated precision current sources for loop compensation and fault
protection circuitry. When compared to a discrete MOSFET
and controller or RCC switching converter solution, the
FSDx321 devices reduce total component count, design size,
weight while increasing efficiency, productivity and system
reliability. Both devices provide a basic platform that is well
suited for the design of cost-effective flyback converters.