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.
- TV/MONITOR SMPS
- BLUE ANGEL, ENERGY STAR, ENERGY 2000 COMPLIANT
- DIGITAL CONSUMER
- AC-DC ADAPTERS/CHARGERS
- PRINTERS, FAX MACHINES, PHOTOCOPIERS AND SCANNERS
- 1% PRECISION (@ Tj = 25˚C) INTERNAL REFERENCE VOLTAGE
- DISABLE FUNCTION (ON/OFF CONTROL)
- QUASI-RESONANT (QR) ZERO-VOLTAGE-SWITCHING (ZVS) TOPOLOGY
- FREQUENCY FOLDBACK FOR OPTIMUM STANDBY EFFICIENCY
- LINE FEED FORWARD TO DELIVER CONSTANT POWER vs. MAINS CHANGE
- ULTRA-LOW START-UP (< 70µA) AND QUIESCENT CURRENT (< 3.5mA)
- ±400mA TOTEM POLE GATE DRIVER WITH UVLO PULL-DOWN
- PULSE-BY-PULSE & HICCUP-MODE OCP