bq2114
NiCd or NiMH Gas Gauge Module
with Charge-Control Output
Features
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Complete bq2014 Gas Gauge solution for NiCd or
NiMH battery packs
Charge-control output allows communication to
external charge controller (bq2004)
Battery information available over a single-wire
bidirectional serial port
Battery state-of-charge monitoring for 4- to 12-cell
series applications
On-board regulator allows direct connection to the
battery
“L” version includes push-button activated LEDs to
display state-of-charge information
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Nominal capacity and cell chemistry pre-configured
Compact size for battery pack integration
A module development kit is also available for the
bq2114. The bq2114B-KT or bq2114LB-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.
General Description
2) Menu-driven software with the bq2114 to display
charge/discharge activity and to allow user inter-
face to the bq2014 from any standard DOS PC.
The bq2114 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 bq2114 incorporates a bq2014 Gas Gauge IC, a
current sense resistor, and all other components neces-
sary to accurately monitor and display the capacity of 4
to 12 series cells. The bq2114L includes five surface-
mounted LEDs to display remaining capacity in 20% in-
crements of the learned capacity (relative mode). The
LEDs are activated with the onboard push-button
switch.
3) Source code for the TSR.
Pin Descriptions
DQ/Serial communication port
BAT+/Battery positive/pack positive
CHG/Charge control output
EMPTY/Empty indicator output
GND/Ground
P1
P2
P3
P4
P5
P6
P7
Contacts are provided on the bq2114 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
bq2014 data sheet for the specifics on the operation of
the Gas Gauge.
PACK-/Pack negative
Unitrode configures the bq2114 based on the informa-
tion requested in Table 1. The configuration defines the
number of series cells, the nominal battery pack capac-
ity, and the self-discharge rate.
BAT-/Battery negative
5/99 B
1