A Product Line of Diodes Incorporated APR343
SECONDARY SIDE SYNCHRONOUS RECTIFICATION CONTROLLER Description
APR343 is a secondary side MOSFET driver for synchronous rectification in DCM operation, which integrates the output voltage detection function for primary side control system. The synchronous rectification can effectively reduce the secondary side rectifier power dissipation and provide high performance solution. By sensing MOSFET drain-to-source voltage, APR343 can output ideal drive signal with less external components. It can provide high performance solution for 5V output voltage application. Same as AP4341, APR343 detects the output voltage and provides a periodical signal when the output voltage is lower than a certain threshold. By fast response to secondary side voltage, APR343 can effectively improve the transient performance of primary side control system. The APR343 is available in SOT25 package. Pin Assignments
(Top View) DRISR GND VCC 1 2 3 5 VDET NEW PRODUCT 4 AREF SOT25 Features Synchronous Rectification for DCM Operation Flyback Eliminate Resonant Ring Interference Fast Detector of Supply Voltage Fewest External Components Totally Lead-free & Fully RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free. "Green" Device (Note 3) Applications Adapters/Chargers for Cell/Cordless Phones, ADSL Modems, MP3 and Other Portable Apparatus Standby and Auxiliary Power Supplies Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant. 2. See http://www.diodes.com/quality/lead_free.html for more information about Diodes Incorporated's definitions of Halogen- and Antimony-free, "Green" and Lead-free. 3. Halogen- and Antimony-free "Green" products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and <1000ppm antimony compounds. Typical Applications Circuit
T1 C20 Q2 C22
1 DRISR 3 VCC + R21
5 VDET R22 APR343
AREF 4 GND 2 C21 R20 APR343
Document number: DS36884 Rev. 4 - 2 1 of 12 www.diodes.com December 2014
© Diodes Incorporated A Product Line of Diodes Incorporated APR343 Pin Descriptions Pin Number 1 2 3 Pin Name DRISR GND VCC AREF VDET Synchronous rectification MOSFET Gate drive Ground Power supply, connected with system output Function NEW PRODUCT 4 5 Program a voltage reference with a resistor from AREF to GND, to enable synchronous rectification MOSFET drive signal Synchronous rectification sense input and dynamic function output, connected with secondary winding Functional Block Diagram
VCC
3 VREF Integrator ( VDET -VCC )* tONP VDET IOVP Dynamic OVP I …