1

Micropower Voltage Reference with Comparator

ISL21440

The ISL21440 is a micropower, FGA™ reference and comparator

on a single chip. Drawing less than 1.8µA supply current over the

single 2V to 11V supply and can also be used with split bipolar

supplies.

The ISL21440’s on-board reference provides a 1.182V ±0.5%

output. It features programmable hysteresis and TTL/CMOS

compatible outputs that sink and source current. Low Bias

currents permit high value divider resistors for typical circuit

current drains of <2.5µA.

The low supply current makes the ISL21440 ideal for battery

powered devices in battery level or low voltage monitors circuits.

The ISL21440 is a pin-compatible, performance upgrade of both

the LTC1440, LTC1540, MAX921 and MAX931.

Features

• 1.8µA Supply Current Over Full Temperature Range

• Wide Supply Range . . . . . . . . . . . . . . . . . . . . . . . . . . 2V to 11V

• Precision 1.182V ±0.5% Voltage Reference

• Comparator with User Programmable Hysteresis

• Temperature Range . . . . . . . . . . . . . . . . . . . .-40°C to +125°C

• 8 Ld MSOP and 8 Ld TDFN Packages

• Pin Compatible Upgrade to MAX921 and LTC1440

Applications

•Low Battery Detector

•Low Voltage Reset

•Overvoltage Monitor

• Window Comparator

FIGURE 1. TYPICAL APPLICATION

FIGURE 2. REFERENCE VOLTAGE vs TEMPERATURE

V+

OUT

IN-

HYST

GND

V-

REF

IN+

ISL21440

-

+

VBAT

Vdd

2.4M

20k

LoBAT-

2.4M

1.8M

LOW BATTERY DETECTOR

1.172

1.174

1.176

1.178

1.180

1.182

1.184

1.186

1.188

1.190

-40

-20

0

20

406080

100

120

TEMPERATURE (°C)

V+ = 5V

V+ = 2V

V+ = 3V

February 23, 2011

FN6532.2

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

1-888-INTERSIL or 1-888-468-3774

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