PPMIC BU

www.belling.com.cn

BL3406B Rev 1.5

Belling Proprietary Information. Unauthorized Photocopy and Duplication Prohibited

10/2009

©2009 Belling All Rights Reserved

1

BL3406B

1.5 MHz, 800mA Synchronous Buck Converter

FEATURES

• High Efficiency: Up to 96%

• 1.5MHz Constant Switching Frequency

• Current Mode Operation for Excellent

Line and Load Transient Response

• No Schottky Diode Required

• 2.5V to 5.5V Input Voltage Range

• 1.0V,1.2V,1.5V,1.8V,2.5V and 3.3V

Fixed/Adjustable Output Voltage

• 100% Duty Cycle in Dropout Mode

• Low Quiescent Current: 180µA

• Over temperature Protection

• Short Circuit Protection

• Shutdown Quiescent Current < 1µA

• Space Saving 5-Pin Thin SOT23 Package

APPLICATIONS

• Cellular and Smart Phones

• Wireless Handsets and DSL Modems

• Microprocessors and DSP Core Supplies

• PDAs

• Digital Still and Video Cameras

• MP3/MP4/MP5 Players

• Portable Instruments

• GPS Receivers

DESCRIPTION

The

BL3406B is

a constant frequency,

1.5MHz, slope compensated current mode

PWM step-down converter working under an

input voltage range of 2.5V to 5.5V. This

feature makes the BL3406B suitable for

single cell Li-ion battery-powered applications.

The internal synchronous rectifier is desired

to increase efficiency without an external

Schottky diode. 100% duty cycle capability

extends battery life in portable devices, while

the quiescent current is 180µA at no load,

and drops to < 1µA in shutdown. Pulse

Skipping Mode operation increases efficiency

at light loads, further extending battery life.

The BL3406B is offered in a low profile (1mm)

5-pin, thin SOT23 package, and is available

in an adjustable version and fixed output

versions of 1.0V, 1.2V, 1.5V , 1.8V, 2.5V and

3.3V.

ORDERING INFORMATION

TYPICAL APPLICATION

BL3406B –XX X XXX

Run

GND

SW

V

IN

V

FB

BL3406B-ADJ

4

1

2

3

5

L1

2.2 H

C3

10uF

C2

22pF

R2

200k

R1

100k

V

2.7V - 4.2V

C1

4.7uF

Figure 1. BL3406B-ADJ Typical Application Circuit

Package：

TRN: TSOT23-5

RN: SOT23-5

Output Voltage：

10: 1.0V

12: 1.2V

15: 1.5V

18: 1.8V

25: 2.5V

33: 3.3V

AD: Adjustable

Features:

P: Standard (default,

lead free)

C: Customized