Texas Instruments bq27220, User Manual, Page: 8 / 20

Operation
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8 SLUUBF5 – April 2016
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bq27220EVM-744 Evaluation Module
3.3 Calibration
The bq27220EVM must be calibrated to ensure accurate value reporting. Calibrate the EVM in the
Calibration window in bqStudio ( Figure 4 ).
Figure 4. Calibration Screen
Calibration consists of the following:
• CC Offset/Board Offset: Check Calibrate CC Offset and Calibrate Board Offset , then click the
Calibrate Gas Gauge button to calibrate the Coulomb counter and board offsets. Ensure no current is
flowing through the sense resistor during these steps. After a successful calibration, a green check
mark shows next to the
Calibrate Gas Gauge button.
• Current: Connect a 2-A load to LOAD+/LOAD– or a current source to LOAD–/PACK–. Ensure the
measured current reported is negative, or else reverse the connections. Check
Calibrate Current and
enter the current into the textbox then click the Calibrate Gas Gauge button.
• Voltage: Apply a known DC voltage to PACK+/PACK– with no current flowing through the sense
resistor. Check
Calibrate Voltage and enter the voltage into the textbox then click the Calibrate Gas
Gauge button.