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SLUUA63A–April 2013–Revised July 2016
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bq27421 EVM: Single-Cell Impedance Track Technology
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User's Guide
SLUUA63A–April 2013–Revised July 2016
bq27421 EVM: Single-Cell Impedance Track Technology
This evaluation module (EVM) is a complete evaluation system for the bq27421. The EVM includes one
bq27421 circuit module with an integrated current-sense resistor. A separated orderable EV2300 or
EV2400 PC interface board for gas gauge interface along with a PC USB cable, and Microsoft®Windows®
based PC software is needed when using this EVM. The circuit module includes one bq27421 integrated
circuit and all other onboard components necessary to monitor and predict capacity for a system-side fuel
gauge solution. The circuit module connects directly across the battery pack. With the EV2300 or EV2400
interface board and software, the user can:
• Read the bq27421 data registers
• Update the RAM for different configurations
• Log cycling data for further evaluation
• Evaluate the overall functionality of the bq27421 solution under different charge and discharge
conditions
The latest Windows-based PC software can be downloaded from the product folder on the Texas
Instruments Web site.
Contents
1 Features....................................................................................................................... 2
1.1 Kit Contents.......................................................................................................... 2
1.2 Ordering Information ............................................................................................... 2
2 bq27421-Based Circuit Module ............................................................................................ 3
2.1 Circuit Module Connections ....................................................................................... 3
2.2 Pin Description...................................................................................................... 3
3 Circuit Module Physical Layout, Bill of Materials and Schematic...................................................... 4
3.1 Board Layout ........................................................................................................ 4
3.2 Bill of Material ....................................................................................................... 7
3.3 Schematic............................................................................................................ 7
3.4 bq27421 Circuits Module Performance Specification Summary.............................................. 8
4 EVM Hardware and Software Setup ...................................................................................... 8
4.1 Software Installation................................................................................................ 8
5 Troubleshooting Unexpected Dialog Boxes.............................................................................. 8
6 Hardware Connection ....................................................................................................... 9
6.1 Connecting the bq27421 Circuit Module to a Battery Pack ................................................... 9
6.2 PC Interface Connection........................................................................................... 9
7 Operation.................................................................................................................... 10
7.1 Starting the Program.............................................................................................. 10
7.2 Setting Programmable bq27421 Options ...................................................................... 11
8 Calibration................................................................................................................... 13
8.1 Calibrating the bq27421 ......................................................................................... 13
8.2 Voltage Calibration................................................................................................ 13
8.3 Board Offset Calibration.......................................................................................... 13
9 Advanced Communication I2C............................................................................................ 14
9.1 I 2C Communication............................................................................................... 14
10 Related Documentation from Texas Instruments ...................................................................... 16
