General Description

The MAX6439–MAX6442 are a family of ultra-low-power

battery monitors with integrated microprocessor (µP)

supervisors. The battery monitors are offered with sin-

gle or dual low-battery output options that can be used

to signal when the battery is OK (enabling full system

operation), when the battery is low (for low-power sys-

tem operation), and when the battery is dead (to dis-

able system operation). These devices also have an

vides an active-low reset output. A manual reset func-

tion is available to reset the µP with a push-button. No

external components are required.

The MAX6439–MAX6442 are offered with several facto-

ry-trimmed low-battery threshold combinations ideal for

single-cell lithium-ion (Li+) or multicell alkaline/NiCd/

NiMH applications. When the battery voltage drops

below each specified low threshold, the low-battery out-

puts are asserted to alert the system. When the voltage

rises above the specified high thresholds, the outputs

are deasserted after a 150ms minimum timeout period,

ensuring the voltages have stabilized before power cir-

cuitry is activated or providing microprocessor reset tim-

ing. The low and high thresholds provide hysteresis in

battery-operated systems to eliminate output chattering.

The MAX6439/MAX6440 offer factory-trimmed battery

monitors with a single output. The MAX6441/MAX6442

offer factory-trimmed battery monitors with dual outputs.

All battery monitors have open-drain low-battery outputs.

The MAX6439–MAX6442 monitor system voltages

options. Each device is offered with two minimum reset

timeout periods of 150ms or 1200ms. The MAX6439/

MAX6441 are offered with an open-drain RESET output

and the MAX6440/MAX6442 are offered with a push-

pull RESET output.

The MAX6439–MAX6442 are offered in a SOT23 pack-

age and are fully specified over a -40°C to +85°C temp-

erature range.

Applications

Battery-Powered Systems (Single-Cell Li+ or

Two-/Three-Cell NiMH, NiCd, Alkaline)

Cell Phones/Cordless Phones

Portable Medical Devices

Electronic Toys

Pagers

PDAs

MP3 Players

Features

Monitoring Single-Cell Li+ or Multicell

Alkaline/NiCd/NiMH Applications

o Immune to Short Battery Voltage Transients

o Low Current (2.5µA typ at 3.6V)

o Single and Dual Low-Battery Output Options

o 150ms Minimum LBO Timeout Period

o Independent µP Reset with Manual Reset

from 1.8V to 3.3V

Reset Timeout Period Options

o -40°C to +85°C Operating Temperature Range

o Small 6- and 8-Pin SOT23 Packages

o No External Components

Low-Power, Single-/Dual-Level Battery Monitors

with Hysteresis and Integrated µP Reset

________________________________________________________________ Maxim Integrated Products

1

MR

RESET

LBO

16

5

GND

MAX6439

MAX6440

SOT23-6

TOP VIEW

2

34

Pin Configurations

Ordering Information

19-2535; Rev 0; 7/02

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

PART

TEMP RANGE

PIN-PACKAGE

MAX6439UT_ _ _D_-T

-40°C to +85°C

6 SOT23-6

MAX6440UT_ _ _D_-T

-40°C to +85°C

6 SOT23-6

MAX6441KA_ _ _D_-T

-40°C to +85°C

8 SOT23-8

MAX6442KA_ _ _D_-T

-40°C to +85°C

8 SOT23-8

Note: The first two “_ _” are placeholders for the battery moni-

tor voltage levels. Desired threshold levels are set by the part

reset threshold level suffix found in Table 3. The “_” after the D

is a placeholder for the reset timeout period suffix found in

Table 4. All devices are available in tape-and-reel only. There

is a 2500-piece minimum order increment for standard ver-

sions. Sample stock is typically held on standard versions only.

Nonstandard versions require a minimum order increment of

10,000 pieces. Contact factory for availability.

Pin Configurations continued at end of data sheet.