Product Summary

The DH321 is a Green Mode Fairchild Power Switch. The DH321 consists of an integrated Pulse Width Modulator (PWM) and Sense FET, and is specifically designed for high performance off-line Switch Mode Power Supplies(SMPS) with minimal external components. It is integrated high voltage power switching regulators which combine an avalanche rugged Sense FET with a current mode PWM control block.

Parametrics

DH321 absolute maximum ratings: (1)Drain Pin Voltage:650 V; (2)Vstr Pin Voltage:650 V; (3)Drain-Gate Voltage:650 V; (4)Gate-Source Voltage:±20 V; (5)Drain Current Pulsed:1.5 A; (6)Continuous Drain Current (Tc=25℃):0.7 A; (7)Continuous Drain Current (Tc=100℃):0.32 A; (8)Single Pulsed Avalanche Energy:10 mJ; (9)Supply Voltage:20 V; (10)Feedback Voltage Range:-0.3V to VCC; (11)Total Power Dissipation:1.40 W; (12)Operating Junction Temperature:Internally limited; (13)Operating Ambient Temperature:-25℃ to +85℃; (14)Storage Temperature:-55℃ to +150℃.

Features

DH321 features: (1)Internal Avalanche Rugged Sense FET; (2)Consumes only 0.65W at 240VAC & 0.3W load with Advanced Burst-Mode Operation; (3)Frequency Modulation for EMI Reduction; (4)Precision Fixed Operating Frequency; (5)Internal Start-up Circuit; (6)Pulse-by-Pulse Current Limiting; (7)Abnormal Over Current Protection (AOCP); (8)Over Voltage Protection (OVP); (9)Over Load Protection (OLP); (10)Internal Thermal Shutdown Function (TSD); (11)Auto-Restart Mode; (12)Under Voltage Lockout (UVLO); (13)Low Operating Current (max 3mA); (14)Adjustable Peak Current Limit; (15)Built-in Soft Start.

Diagrams

DH321 block diagram