bq2111L

The bq2111L Gas Gauge Module provides a complete and compact solution for capacity monitoring of NiCd battery packs in high discharge rate applications such as power tools. Designed for battery pack integration, the bq2111L incorporates a bq2011 Gas Gauge IC, five surface-mounted LEDs, and the other discrete components necessary to monitor and display accurately the capacity of 4- to 12 -series cells.  The only external compo-nent required is a low-value sense resistor connected between GND and PACK-. Contacts are also provided on the bq2111L for direct connection to the battery stack and the serial communications port (DQ). The battery stack should be connected between BAT+ and GND Please refer to the bq2011 data sheet for the specifics on theoperationoftheGasGauge.


Unitrode configures the bq2111L based on the information requested in Table 1. The configuration defines the number of series cells and the nominal battery pack capacity. The bq211L module uses the absolute LED display to indicate battery capacity. In this mode, the remaining capacity is represented as a percentage of the programmedcapacity.


The bq2111L can operate directly from four series cells within the pack using the LBAT+ supply input. For four series cell applications or applications using the onboard regulator, LBAT+ should be connected to BAT+.Please refer to Figure 1 for module connection illustrations.


A module development kit is also available for the bq2111L. The bq2111LB-KT includes one configured moduleandthefollowing:
1) An interface board that allows connection to the serialportofanAT-compatiblecomputer.
2) Menu-driven software with the bq2111L to display charge/discharge activity and to allow user interfacetothebq2011fromanystandardDOSPC.
3) SourcecodefortheTSR.