BQ2112 Datasheet, PDF (1/7 Pages) Texas Instruments – NiCd or NiMH Gas Gauge Module with Slow-Charge Control

bq2112
NiCd or NiMH Gas Gauge Module
with Slow-Charge Control
Features
ä Complete bq2012 Gas Gauge solution for NiCd or
NiMH battery packs
ä Output for slow-charge control of battery pack
ä Battery information available over a single-wire
bidirectional serial port
ä Battery state-of-charge monitoring for 4- to 12-cell
series applications
ä On-board regulator allows direct connection to the
battery
ä “L” version includes push-button activated LEDs to
display state-of-charge information
ä Nominal capacity and cell chemistry pre-configured
ä Compact size for battery pack integration
General Description
The bq2112 Gas Gauge Module provides a complete and
compact solution for capacity monitoring of NiCd and
NiMH battery packs. Designed for battery pack integra-
tion, the bq2112 incorporates a bq2012 Gas Gauge IC, a
current sense resistor, and all other components neces-
sary to accurately monitor and display the capacity of 3
to 12 series cells. The bq2112L includes six surface-
mounted LEDs to display remaining capacity in 20% in-
crements of the learned capacity (relative mode) or pro-
grammed capacity (absolute mode). The sixth LED is
used in absolute mode to represent an overfull condition
(charge above the programmed capacity). The LEDs are
activated with the onboard push--button switch.
Contacts are provided on the bq2112 for direct connec-
tion to the battery stack (BAT+, BAT-), the serial com-
munications port (DQ), the empty indicator (EMPTY),
and the charge control output (CHG). Please refer to the
bq2012 data sheet for the specifics on the operation of
the Gas Gauge.
Unitrode configures the bq2112 based on the informa-
tion requested in Table 1. The configuration defines the
number of series cells, the nominal battery pack capac-
ity, the self-discharge rate, and the LED display mode.
A module development kit is also available for the
bq2112. The bq2112B-KT or bq2112LB-KT includes one
configured module and the following:
1) An interface board that allows connection to the se-
rial port of an AT-compatible computer.
2) Menu-driven software with the bq2112 to display
charge/discharge activity and to allow user inter-
face to the bq2012 from any standard DOS PC.
3) Source code for the TSR.
Pin Descriptions
P1
DQ/Serial communication port
P2
BAT+/Battery positive/pack positive
P3
CHG/Charge control output
P4
EMPTY/Empty indicator output
P5
GND/Ground
P6
PACK-/Pack negative
P7
BAT-/Battery negative
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