APR347 SECONDARY SIDE SYNCHRONOUS RECTIFICATION CONTROLLER Description Pin Assignments (Top View) The APR347 is a secondary side MOSFET driver for synchronous rectification in DCM operation. Pin 1 Mark The synchronous rectification can effectively reduce the secondary side rectifier power dissipation and provide high performance solution. 6 DRISR AREF 1 By sensing primary MOSFET gate-to-source voltage, the APR347 can output ideal drive signal with less external components. VDD GND 2 5 The APR347 is available in the SOT26 package. VCC 3 4 VDET SOT26 Applications Features Synchronous Rectification for DCM Operation Flyback Adapters/Chargers for Cell/Cordless Phones, ADSL Modems, Eliminate Resonant Ring Interference MP3 and Other Portable Apparatus Fewest External Components Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) Halogen- and Antimony-Free. Green Device (Note 3) For automotive applications requiring specific change control (i.e. parts qualified to AEC-Q100/101/200, PPAP capable, and manufactured in IATF 16949 certified facilities), please contact us or your local Diodes representative. APR347 Pin Descriptions Pin Number Pin Name Function Program a voltage reference with a resistor from AREF to GND, to enable synchronous rectification 1 AREF MOSFET drive signal 2 GND Ground 3 VDET SR MOS drain-to-source voltage sense input, connected to drain pin of SR MOSFET through a resistor Power supply, connected with system output 4 VCC Input of internal LDO and system output voltage sensing circuit. Internal power supply. It provides bias voltage for the internal logic circuit and the MOSFET driver. 5 VDD Connect this pin to a capacitor. 6 DRISR Synchronous rectification MOSFET Gate drive Functional Block Diagram VCC 4 Test VDET Mode I AREF LDO PLR Fault 1 Mode AREF S1 5 VDD VCC S Q Integrator (VDET-VCC)dt V REF R V THON S Q 6 Drive DRISR R LEB 3 Time VDET Gate Monitor V THOFF Light Load Control 2 GND 2 of 9 December 2020 APR347 Diodes Incorporated www.diodes.com Document number: DS41207 Rev. 5 - 2