®
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
■
Small 8 Pin MSOP Package
■
Flexibility to Optimize Inductor Type with
Programmable Peak Current Control
■
No External FETs
V B AT 1
B AT T L 0 2
RLIM 3
SHDN 4
SP6644
SP6645
8 Pin MSOP
8
V
OUT
7
LX
6
GND
4
FB
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
22µH
0.7A
0.88V to
3.3V Input
47µF
R
LIM
V
BATT
LX
V
OUT
+3.3V
OUT
SP6644
SP6645
47µF
BATTLO
SHDN
GND
FB
Rev:B Date 4/13/04
SP6644/6645 High Efficiency Boost Regulator
© Copyright 2004 Sipex Corporation
1
SIPEX [ SIPEX CORPORATION ]
