bq27421-Based Circuit Module
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SLUUA63A – April 2013 – Revised July 2016
Copyright © 2013–2016, Texas Instruments Incorporated
bq27421 EVM: Single-Cell Impedance Track Technology
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bq27421-Based Circuit Module
The bq27421-based circuit module is a complete and compact example solution of a bq27421 circuit for
battery management. The circuit module incorporates a bq27421 battery gas gauge integrated circuit (IC)
with integrated sense resistor and all other components necessary to accurately predict the capacity of a
1-series Li-ion cell.
2.1
Circuit Module Connections
Contacts on the circuit module provide the following connections:
•
Direct connection to the battery pack (J5): PACK+, PACK–
•
To the serial communications port (J10): SDA, SCL, and VSS
•
The system load and charger connect across charger and load (J6 and J7): /LOAD+ and
CHARGER–/LOAD–.
•
Access to signal outputs (J1 and J5): BIN and GPOUT
•
External connect to power the IC (J4): EXT VDD and VSS
2.2
Pin Description
Pin Name
Description
PACK+
Pack positive terminal
PACK–
Pack negative terminal
SDA
I
2
C communication data line
EXT VDD
External supply connection
SCL
I
2
C communication clock line
VSS
Signal return for communication line, shared with charger and ground
/LOAD+
High potential of load or charger connection
CHARGER–/LOAD–
Low potential of load or charger connection (system VSS)
BIN
Battery insertion detection input
GPOUT
General purpose output