SLUUCY8 December 2023 BQ77307
The BQ77307 device integrates a diagnostic check on the voltage references used by the device. A regular check is made of the ratio between the two reference voltages every CHECK interval. Thus, if one of the two references malfunctions and deviates significantly from its expected value, the resulting ratio result changes and allows detection of this condition. When detected, the device triggers a Voltage Reference Diagnostic Fault and sets 0x03 Safety Status B()[VREF], if enabled, and the device can disable FETs based on settings in Settings:Protection:Both FET Protections B[VREF]. The fault can be recovered by the host sending the 0x009B PROT_RECOVERY()[DIAGREC] subcommand. The diagnostic protection alert is triggered whenever the deviates from the expected value by approximately 25%. The diagnostic protection status fault is triggered when this occurs for two consecutive CHECK intervals.