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Date: 3/6/06

SP6656, 400mA Synchronous Buck Regulator with Dynamically Adjustable Voltage Output

© Copyright 2006 Sipex Corporation

SP6656

The SP6656 is a 400mA synchronous buck regulator that is ideal for portable applications that

use a Li-Ion or 3 cell alkaline/NiCD/NiMH input. The SP6656’s proprietary control loop, 20µA light

load quiescent current, and 0.3Ω power switches provide excellent efficiency across a wide range

of output currents. As the input battery supply decreases towards the output voltage the SP6656

seamlessly transitions into 100% duty ratio operation further extending useful battery life. The

SP6656 is protected against overload and short circuit conditions with a precise inductor peak

current limit. Other features include externally programmable output voltage down to 1.0V,

dynamically adjustable output voltage, logic level shutdown control, and 140°C over temperature

shutdown.

DESCRIPTION

FEATURES

■ 98% Efficiency Possible

■ Offered in small 2.4 x 2.5mm DFN

■ Ultra-low 20µA Quiescent Current

■ 625mA Inductor Peak Current Limit

■ Guaranteed Minimum 400mA Output

Current

■ 2.7V to 5.5V Input Voltage Range

■ Output Adjustable Down to 1.0V

■ 100% Duty Ratio Low Dropout

Operation

■ 80µA Light Load Quiescent Current in

Dropout

■ Dynamic Adjustable Output Voltage

■ Ideal for portable designs powered with

Li Ion battery

APPLICATIONS

■ Cell Phones

■ PDA's

■ DSC's

■ MP3 Players

■ USB Devices

■ Point of Use Power

TYPICAL APPLICATION SCHEMATIC

Now Available in Lead Free Packaging

High Efficiency 400mA Synchronous Buck Regulator

with Dynamically Adjustable Voltage Output

SP6656

10 Pin DFN

10

9

8

7

6

1

2

3

4

5

VIN

OVSO

OVSI

EN

LX

P

GND

GND

V

OUT

FB

VI

VO

10µF

L1

10µH

400mA

2.7V to 5.5V Input

10Ω

1µF

SP6656

OVSO

EN

LX

GND

FB

10µF

CF

22pF

OVSI

3.2 x 1.6 x 1.55mm