LTC1998

1

1998fa

BLOCK DIAGRAM

FEATURES

APPLICATIONS

DESCRIPTION

2.5µA, 1% Accurate

SOT-23 Comparator and Voltage

Reference for Battery Monitoring

adjustable reference in a 6-pin SOT-23 package that is

optimized for lithium-ion low battery detection circuits.

The LTC1998 features a voltage detection circuit with an

adjustable threshold voltage and hysteresis. The threshold

voltage can be programmed from 2.5V to 3.25V with two

external resistors. A 10mV to 750mV hysteresis can be

added with a third external resistor.

A proprietary internal architecture maintains 1% thresh-

old voltage accuracy over temperature with low cost 1%

external resistors.

logic output to operate below the battery voltage, allowing

compatibility with low voltage microprocessors without a

pull-up resistor. Power supply glitches are eliminated by

preventing the cross-conducting current which occurs

when the output changes state.

The LTC1998 operates with battery or supply voltages

up to 5.5V and its battery-low output is valid for battery

voltages above 1.5V.

Threshold Voltage Error vs Temperature

External 1% Resistors

PDAs

Cell Phones

Handheld Instruments

Battery Packs

Pagers

Palm Top Computers

POS Terminals

L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. ThinSOT is

a trademark of Linear Technology Corporation. All other trademarks are the property of their

respective owners.

1998 BD

THRESHOLD

ADJUST

BATT

BATTLO

1.1R

R

1.2V

TEMPERATURE (°C)

–45

15

55

1998 TA02

–25

–5

35

75

95

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

EXTERNAL R,

THRESHOLD = 3V

THRESHOLD = 3V

TO GROUND,

THRESHOLD = 2.5V