Description

The AP3771 is a high performance AC/DC power supply controller for

battery charger and adapter applications. The device uses Pulse

Frequency Modulation (PFM) method to build discontinuous

conduction mode (DCM) flyback power supplies.

The AP3771 provides accurate constant voltage, constant current

(CV/CC) regulation without requiring an opto-coupler and the

secondary control circuitry. It also eliminates the need of loop

compensation circuitry while maintaining good stability. The AP3771

can achieve excellent regulation and high average efficiency, yet

meets no-load consumption less than 30mW. It can also achieve

excellent dynamic performance while maintaining 30mW standby

power with AP4340.

The AP3771 has a built-in fixed cable voltage drop compensation

function. The cable compensation voltage is set as 7% and 3% of the

rated output voltage. It also has an adjustable built-in line

compensation function to achieve tight CC.

The AP3771 drives MOSFET to achieve the high switching frequency

and high efficiency.

The AP3771 is available in SOT26 package.

Features

Primary Side Control for Tight Constant Current and Constant

Voltage

30mW No-load Input Power

Excellent Dynamic Performance with AP4340 (For 5V

Application)

MOSFET Driving

Proprietary Adjustable Line Compensation for CC Variation

Constant and Built-in 7% and 3% Voltage Drop Compensation

Enhanced Audio Noise Suppression

Open Circuit Protection

Over Voltage Protection

Short Circuit Protection

SOT26 Package

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

Halogen and Antimony Free. “Green” Device (Note 3)

Applications

Adapters/Chargers for Cell/Cordless Phones, PDAs, MP3 and

Other Portable Devices

LED Driver

Standby and Auxiliary Power Supplies