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Date: 11/30/04

SP6644/6645 High Efficiency Boost Regulator

© Copyright 2004 Sipex Corporation

SP6644/6645

Single/Dual Alkaline Cell, High Efficiency

Boost DC-DC Regulator

■ 90mA Output Current at 1.3V Input

■ 190mA Output Current at 2.6V Input

■ +2V to +5.5V Output Range

■ 0.88V Guaranteed Start-Up

■ 92% High Efficiency

■ 1.6µA Quiescent Supply Current at V

BATT

■ Reverse Battery Protection

■ Internal Synchronous Rectifier

■ 5nA Logic Controlled Shutdown Current

From V

BATT

■ Low-Battery Detection Active LOW Output

GND

FB

LX

47µF

47µF

SHDN

22µH

0.7A

0.88V to

3.3V Input

SP6644

SP6645

BATTLO

®

DESCRIPTION

The SP6644/6645 devices are high-efficiency, low-power step-up DC-DC converters ideal

for single or dual alkaline cell applications such as pagers, remote controls, pointing devices,

medical monitors, and other low-power portable end products. Designers can control the

SP6644 device with an active LOW shutdown input. The SP6644 device features an active

low output for batteries below +1.0V. The SP6645 device features an active low output for

batteries below +2.0V. Both devices contain a 0.8Ω synchronous rectifier, a 0.5Ω

N-channel MOSFET power switch, an internal voltage reference, circuitry for pulse-

frequency-modulation, and an under voltage comparator.

The output voltage for the

SP6644/6645 devices is preset to +3.3V + 4% or can be adjusted from +2V to +5.5V by

manipulating two external resistors

TYPICAL APPLICATION CIRCUIT

SP6644

SP6645

8 Pin MSOP

8

7

6

4

LX

GND

FB

V BAT

BATTL0

R LIM

SHDN

1

2

3

4

Now Available in Lead Free Packaging

■ Small 8 Pin MSOP Package

■ No External FETs

■ Flexibility to Optimize Inductor Type

with Programmable Peak Current

Control