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BCD Semiconductor Manufacturing Limited reserves the right to make changes without further notice to any products or specifi-

cations herein. BCD Semiconductor Manufacturing Limited does not assume any responsibility for use of any its products for any

particular purpose, nor does BCD Semiconductor Manufacturing Limited assume any liability arising out of the application or use

of any its products or circuits. BCD Semiconductor Manufacturing Limited does not convey any license under its patent rights or

other rights nor the rights of others.

- Wafer Fab

Shanghai SIM-BCD Semiconductor Manufacturing Limited

800, Yi Shan Road, Shanghai 200233, China

Tel: +86-21-6485 1491, Fax: +86-21-5450 0008

BCD Semiconductor Manufacturing Limited

MAIN SITE

REGIONAL SALES OFFICE

Shenzhen Office

Shanghai SIM-BCD Semiconductor Manufacturing Co., Ltd. Shenzhen Office

Advanced Analog Circuits (Shanghai) Corporation Shenzhen Office

Room E, 5F, Noble Center, No.1006, 3rd Fuzhong Road, Futian District, Shenzhen 518026, China

Tel: +86-755-8826 7951

Fax: +86-755-8826 7865

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BCD Semiconductor (Taiwan) Company Limited

4F, 298-1, Rui Guang Road, Nei-Hu District, Taipei,

Taiwan

Tel: +886-2-2656 2808

Fax: +886-2-2656 2806

USA Office

BCD Semiconductor Corporation

30920 Huntwood Ave. Hayward,

CA 94544, U.S.A

Tel : +1-510-324-2988

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- IC Design Group

Advanced Analog Circuits (Shanghai) Corporation

8F, Zone B, 900, Yi Shan Road, Shanghai 200233, China

Tel: +86-21-6495 9539, Fax: +86-21-6485 9673

BCD Semiconductor Manufacturing Limited

http://www.bcdsemi.com

BCD Semiconductor Manufacturing Limited

Description

The AP3605 is a step-up DC/DC converter based on 1.5x

charge pump current source, it is specially designed for

LED supplies in backlight display.

The AP3605 can provide constant current up to 20mA for

each LED, which is programmed by an external resistor,

so it has a total capability to provide 80 mA for 4 LEDs.

The chip has a good performance of LED current

matching and allows PWM brightness dimming control.

Additionally, high switching frequency up to 1 MHz

enables the use of two small external flying capacitors.

Internal soft-start circuitry prevents excessive inrush

current during start-up.

The AP3605 supply voltage range is from 2.7V to 5.5 V,

ideally suited for applications powered by the Li-ion

battery.

The AP3605 is available in a 3mm*3mm QFN-3x3-16

Features

·

Regulated Output Current with

±3% Matching

·

Regulated

±10% Output Current Source

·

Drive up to 4 LEDs at 20 mA Each

·

Wide Operating Voltage Range: 2.7V to 5.5V

·

High Efficiency up to 93%

·

High Operating Frequency: 1MHz

·

Built-in Soft-Start to Limit the Inrush Current

·

LED Brightness Control through PWM and Analog

Signal

·

Built-in Standby Mode to Make PWM Dimming

Control Optimized

·

Built-in OTSD (Over Temperature Shutdown) Func-

tion to Protect the Device from Burn Out

Applications

·

Mobile Phone

·

MP3, MP4

·

White LED Backlight in Mobile Phone, PDA

Benefits

·

Wide Input Voltage Range

·

High Current Matching Precision

·

Built-in Standby to Make PWM Dimming Control

Optimized

Additional Available Materials

·

Samples

·

Preliminary Datasheet

·

Demo Board

·

Application Note

·

ESD Report

Jul. 2007

BCD Semiconductor Manufacturing Limited

Product Brief

CHARGE PUMP CURRENT SOURCE FOR LED DRIVER WITH BRIGHTNESS CONTROL

AP3605

Parametric Table

Input Voltage (V)

2.7 to 5.5

Supply Current (Typ) (mA)

1.5

Operating Frequency (Typ) (MHz)

1.0

Efficiency (Typ) (%)

93

Output Current (Max) (mA)

120

Current Matching (Min/Max) (%)

Soft Start Time (Typ) (

µS)

400

Standby Time

(Typ) (ms)

2.0

Package

QFN-3x3-

16