APR34309/A

Document number: DS37412 Rev. 3 - 2

1 of 12

www.diodes.com

June 2015

© Diodes Incorporated

APR34309/A

A Product Line of

Diodes Incorporated

SECONDARY SIDE SYNCHRONOUS RECTIFICATION SWITCHER

Description

APR34309/A is a secondary side Combo IC, which combines an N-

Channel MOSFET and a driver circuit designed for synchronous

rectification (SR) in DCM operation. It also integrates output voltage

detect function for primary side control system.

The N-Channel MOSFET has been optimized for low gate charge,

low RDS(ON), fast switching speed and body diode reverse recovery

performance.

The synchronous rectification can effectively reduce the secondary

side rectifier power dissipation and provide high performance solution.

By sensing MOSFET drain-to-source voltage, APR34309/A can

output ideal drive signal with less external components. It can provide

high performance solution for 5V output voltage application.

Same as AP4341, APR34309/A 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,

APR34309/A can effectively improve the transient performance of

primary side control system.

The APR34309/A is available in SO-8EP package.

Features

•

Synchronous Rectification for DCM Operation Flyback

•

Eliminate Resonant Ring Interference

•

Fast Detector of Supply Voltages

•

Fewest External Components



Totally Lead-free & Fully RoHS Compliant (Notes 1 & 2)



Halogen and Antimony Free.

“Green” Device (Note 3)

Pin Assignments

(Top View)

1

2

3

4

8

7

6

5

DRISR

VDET

AREF

VCC

DRAIN

GND

GND

GND

Note: The DRAIN pin of internal MOSFET is exposed PAD, which is at the bottom

of IC (the dashed box). The secondary current should flow from GND(pin 6,7,8) to

this exposed PAD.

SO-8EP

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 ab

out 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

+

C21

+

C22

APR34309/A

R24

VCC

AREF

DRAIN

DRAIN

GND

GND

VDET

DRISR

RAREF

C23

R21

C24

R23

GND

CAREF