AP3785T Datasheet, PDF(1/18 Page) Diodes Incorporated – PRIMARY SIDE REGULATED SWITCHING MODE POWER SUPPLY CONTROLLER

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AP3785T Datasheet, PDF (1/18 Pages) Diodes Incorporated – PRIMARY SIDE REGULATED SWITCHING MODE POWER SUPPLY CONTROLLER

AP3785T

PRIMARY SIDE REGULATED SWITCHING MODE POWER SUPPLY CONTROLLER

Description

The AP3785T is a high performance AC/DC power supply controller

for battery charger and adapter applications. It can meet less than

10mW standby power for âSuper Starâ charger criteria. The device

uses Pulse Frequency Modulation (PFM) method to build

discontinuous conduction mode (DCM) flyback power supplies.

The AP3785T provides accurate constant voltage (CV), constant

current (CC) and outstanding dynamic performance without requiring

an opto-coupler. It also eliminates the need of loop compensation

circuitry while maintaining stability.

The AP3785T is equipped with both cable drop compensation

function to meet various cables with different lengths and gauges and

adjustable line voltage compensation function.

Pin Assignments

(Top View)

CS 1

EM 2

VCC 3

OUT 4

SO-8

8 FB

7 CBC

6 OTP

5 GND

When AP3785T is used with AP4341 or synchronous rectifier series

(for example APR343 + MOSFET, APR3415, APR34330), better

under-shoot performance and higher conversion efficiency can be

achieved.

The AP3785T has internal over temperature protection for itself, and

also provides dedicated pin for external over temperature protection.

This IC is available in SO-8 package.

Applications

ï· Adapter/Chargers for Shaver, Cell/Cordless Phones, PDAs, MP3

and Other Portable Apparatus

ï· Standby and Auxiliary Power Supplies

Features

ï· Primary Side Control for Eliminating Opto-coupler

ï· 10mW No-load Input Power

ï· Flyback Topology in DCM Operation

ï· External Adjustable Line Compensation for CC

ï· External Adjustable Cable Compensation for CV

ï· Multiple PWM/PFM Control Mode to Improve Audio Noise and

Efficiency

ï· VCS Jitter to Reduce System EMI

ï· Valley-on for the Higher Efficiency and Better EMI

ï· Multiple Protections:

ï· Over Voltage Protection (OVP)

ï· Output Short Circuit Protection (SCP)

ï· Transformer Saturation Protection (TSP) via Primary Peak

Current Limitation

ï· OTP and External Over Temperature Protection (OTP)

ï· Matching AP4341 with Schottky or APR343/APR3415

Synchronous Rectifier Solution

ï· SO-8 Package

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

ï· Halogen and Antimony Free. âGreenâ Device (Note 3)

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 Incorporatedâs definitions of Halogen- and Antimony-free, "Green"

and Lead-free.

3. Halogen- and Antimony-free "Greenâ products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and

<1000ppm antimony compounds.

AP3785T

Document number: DS37552 Rev. 4 - 2

1 of 18

www.diodes.com

September 2015

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