MAX6439 Datasheet, PDF (1/14 Pages) Maxim Integrated Products – Low-Power, Single-/Dual-Level Battery Monitors with Hysteresis and Integrated uP Reset

19-2535; Rev 0; 7/02
Low-Power, Single-/Dual-Level Battery Monitors
with Hysteresis and Integrated µP Reset
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
independent µP supervisor that monitors V_CC and pro-
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
(V_CC) from 1.8V to 3.3V with seven fixed reset threshold
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
o Factory-Trimmed V_BATT Threshold Options for
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
o Factory-Set Reset Thresholds for Monitoring V_CC
from 1.8V to 3.3V
o Available with 150ms (min) and 1.2s (min) V_CC
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
Ordering Information
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
number suffix found in Tables 1 and 2. The third “_” is the V_CC
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
TOP VIEW
V_BATT 1
6 V_CC
MAX6439
MR 2 _MAX6440 5 GND
LBO 3
4 RESET
SOT23-6
Pin Configurations continued at end of data sheet.
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