L6565DTR

The L6565 is a current-mode primary controller IC, specifically designed to build offline Quasi-resonant ZVS (Zero Voltage Switching at switch turn-on) flyback converters. Quasi-resonant operation is achieved by means of a transformer demagnetization sensing input that triggers MOSFET's turn-on. Converter's power capability variations with the mains voltage are compensated by line voltage feedforward. At light load the device features a special function that automatically lowers the operating frequency still maintaining the operation as close to ZVS as possible. In addition to very low start-up and quiescent currents, this feature helps keep low the consumption from the mains at light load and be Blue Angel and Energy Star compliant. The IC includes also a disable function, an on-chip filter on current sense, an error amplifier with a precise reference voltage for primary regulation and an effective two-level overcurrent protection.

Applications

• TV/MONITOR SMPS
• AC-DC ADAPTERS/CHARGERS
• DIGITAL CONSUMER
• PRINTERS, FAX MACHINES, PHOTOCOPIERS AND SCANNERS

Key features

• QUASI-RESONANT (QR) ZERO-VOLTAGE SWITCHING (ZVS) TOPOLOGY
• LINE FEED FORWARD TO DELIVER CONSTANT POWER vs. MAINS CHANGE
• FREQUENCY FOLDBACK FOR OPTIMUM STANDBY EFFICIENCY
• PULSE-BY-PULSE & HICCUP-MODE OCP
• ULTRA-LOW START-UP (<70μA) AND QUIESCENT CURRENT (<3.5mA)
• DISABLE FUNCTION (ON/OFF CONTROL)
• 1% PRECISION (θj = 25°C) INTERNAL REFERENCE VOLTAGE
• ±400mA TOTEM POLE GATE DRIVER WITH UVLO PULL-DOWN
• BLUE ANGEL, ENERGY STAR, ENERGY 2000 COMPLIANT