bq2168

The bq2168 Power Gauge Module provides a complete and compact battery management solution for Li-Ion battery packs. Designed for battery pack integration, the bq2168 combines the bq2050H Power Gauge IC with the bq2058 Supervisor IC on a small printed circuit board. The board includes all the necessary components to accurately monitor battery capacity and protect the cells from overvoltage, undervoltage, and overcurrent onditions. The board works withthreeorfourLi-Ionseriescells.


The Power Gauge IC of bq2168 uses the on-board sense resistor to track charge and discharge activity of the battery pack. Critical battery information can be accessed through the serial communications port at HDQ. The supervisor circuit of bq2168 consists of the bq2058 and two FETs. The bq2058 controls the FETs to protect the batteries during charge/discharge cycles and short circuit conditions. The bq2168 provides contacts for the positive and negative terminals of each battery in the stack. Please refer to the bq2050H and bq2058 data sheets for the specifics on theoperationofthepowergaugeandsupervisorICs.


Unitrode configures the bq2168 based on the information requested in Table 1. The configuration defines the number of series cells, the nominal battery pack capacity, the self-discharge rate, the Li-Ion battery type (cokeor graphite anode), and the threshold limits. Figure 1 showshowthemoduleconnectstothecells.


The bq2168L includes five LEDs to display remaining capacity in 20% increments of the learned capacity. The LEDs are activatedwiththeonboardpush-buttonswitch.


A module development kit of bq2168 is also available for the bq2168. The bq2168B-KT or the bq2168LB-KT includes oneconfiguredmoduleandthefollowing:
1) An EV2200-50H interface board that allows connection to the serial port of any AT-compatible computer.
2) Menu driven software to display charge/discharge activity and to allow user interface to the bq2050H fromanystandardWindows3.1xor95PC.