JAJSKT5B September 2020 – January 2022 BQ769142
PRODUCTION DATA
The BQ769142 device includes optional capabilities for the customer to calibrate the COV (cell overvoltage) and CUV (cell undervoltage) protection thresholds on the production line to improve threshold accuracy in the system, or to realize a threshold between the preset thresholds available from the device.
This calibration is performed while the device is in CONFIG_UPDATE mode. To calibrate the COV threshold, an external voltage is first applied between VC14 and VC13A that is equal to the desired COV threshold. Next, the host sends the CAL_COV() subcommand, which causes the BQ769142 device to perform a search for the appropriate calibration coefficients to realize a COV threshold at or close to the applied voltage level. When this search is completed, the resulting calibration coefficient is returned by the subcommand and automatically written into the Protections:COV:COV Threshold Override configuration parameter. If this parameter is nonzero, the device does not use its factory trim settings, but instead uses this value.
The CUV threshold is calibrated similarly; an external voltage is applied between VC14 and VC13A equal to the desired CUV threshold. Next, while in CONFIG_UPDATE mode, the CAL_CUV() subcommand is sent by the host, which causes the BQ769142 device to perform a search for the appropriate calibration coefficients to realize a CUV threshold at or close to the applied voltage level. When this search is completed, the resulting calibration coefficient is returned by the subcommand and automatically written into the Protections:CUV:CUV Threshold Override configuration parameter.