SP6644 Datasheet, PDF (1/15 Pages) Sipex Corporation – Single/Dual Alkaline Cell, High Efficiency Step-Up DC-DC Converter

®
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
VBAT 1
BATTL0 2
RLIM 3
SHDN 4
SP6644
SP6645
8 Pin MSOP
8 V _OUT
7 LX
6 GND
4 FB
Now Available in Lead Free Packaging
■ Small 8 Pin MSOP Package
■ No External FETs
■ Flexibility to Optimize Inductor Type
with Programmable Peak Current
Control
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
0.88V to
3.3V Input
47µF
22µH
0.7A
VBATT
LX
RLIM
VOUT
SP6644
SP6645
SHDN
GND
FB
47µF
+3.3VOUT
BATTLO
Date: 11/30/04
SP6644/6645 High Efficiency Boost Regulator
1
© Copyright 2004 Sipex Corporation