Features: Complete bq2012 Gas Gauge solution for NiCd or NiMH battery packs
Output for slow-charge control of battery pack
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
Nominal capacity and cell chemistry pre-configured
Compact size for battery pack integrationSpecifications
Symbol |
Parameter |
Minimum |
Maximum |
Unit |
Notes |
VCC |
Relative to VSS |
-0.3 |
+7.0 |
V |
bq2012 |
All other pins |
Relative to VSS |
-0.3 |
+7.0 |
V |
bq2012 |
PSR |
Continuoussenseresis- torpowerdissipation |
- |
3 |
W |
Thru-hole sense resistor |
- |
1 |
W |
Surface-mount sense resistor |
VCHG |
Charging voltage |
- |
3.0 |
A |
|
TOPR |
Operatingtemperature |
0 |
+70 |
°C |
Commercial |
TSTR |
Storage temperature |
-40 |
+85 |
°C |
|
DescriptionThe bq2112 Gas Gauge Module provides a complete and compact solution for capacity monitoring of NiCd and NiMH battery packs. Designed for battery pack integration, the bq2112 incorporates a bq2012 Gas Gauge IC, a current sense resistor, and all other components necessary to accurately monitor and display the capacity of 3 to 12 series cells. The bq2112L includes six surfacemounted LEDs to display remaining capacity in 20% increments of the earned capacity (relative mode) or programmed capacity (absolute mode). The sixth LED is used in absolute mode to represent an overfull condition (charge above the programmed capacity). The LEDs are activatedwiththeonboardpush--buttonswitch.
Contacts are provided on the bq2112 for direct connection to the battery stack (BAT+, BAT-), the serial communications 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 theGasGauge.
Unitrode configures the bq2112 based on the information requested in Table 1. The configuration defines the number of series cells, the nominal battery pack capacity,theself-dischargerate,andtheLEDdisplaymode.
A module development kit is also available for the bq2112. The bq2112B-KT or bq2112LB-KT includes one configuredmoduleandthefollowing:
1) An interface board that allows connection to the serialportofanAT-compatiblecomputer.
2) Menu-driven software with the bq2112 to display charge/discharge activity and to allow user inter facetothebq2012fromanystandardDOSPC.
3) SourcecodefortheTSR.