JAJSEZ9L march 2018 – august 2023 BQ77915
PRODUCTION DATA
Table 9-5 summarizes how each fault condition affects the state of the DSG and CHG output signals, as well as the recovery conditions required to resume charging and/or discharging. As a rule, the CHG and DSG output drivers are enabled only when no respective fault conditions are present. When multiple simultaneous faults (such as an OV and OTD) are present, all faults must be cleared before the FET can resume operation.
FAULT | FAULT TRIGGER CONDITION | CHG | DSG | RECOVERY METHOD | TRIGGER DELAY | RECOVERY DELAY |
---|---|---|---|---|---|---|
CTRC disabled | CTRC disabled for deglitch delay time | OFF | — | CTRC must be enabled for deglitch delay time | tCTRDEG_ON | tCTRDEG_OFF |
CTRD disabled | CTRD disabled for deglitch delay time | — | OFF | CTRD must be enabled for deglitch delay time | ||
OV | V(Cell) rises above VOV for delay time | OFF | — | V(Cell) drops below VOV – VHYS_OV for delay | tOVn_DELAY | |
UV | V(Cell) drops below VUV for delay time | — | OFF | DSG FET turned on after Load is removed and V(Cell) rises above VUV + VHYS_UV for delay. | tUVn_DELAY | |
OW | VCX – VCX–1 < VOW for delay time | OFF | OFF | Bad VCX recovers such that VCX – VCX–1 > VOW + VOW_HYS for delay | tOWn_DELAY | |
OCC | (VSRP – VSRN) > VOCC for delay time | OFF | OFF | Recovery delay expires, OR LD detects > VLDT, OR Recovery delay expires + LD detects > VLDT | tOCC_DELAY | tCD_REC |
OCD1, OCD2, SCD | (VSRP – VSRN) < VOCD1, VOCD2, or VSCD for delay time | OFF | OFF | Recovery delay expires, OR LD detects < VLDT, OR Recovery delay expires + LD detects < VLDT | tOCD1_DELAY, tOCD2_DELAY, tSCD_DELAY | tCD_REC |
OTC(1) | Temperature rises above TOTC for delay time | OFF | — | Temp drops below TOTC – TOTC_REC for delay | tOTC_DELAY | |
OTD(1) | Temperature rises above TOTD for delay time | OFF | OFF | Temp drops below TOTD – TOTD_REC for delay, OR Temp drops below TOTD – TOTD_REC for delay and Load is removed | tOTD_DELAY | |
UTC(1) | Temperature drops below TUTC for delay time | OFF | — | Temperature rises above TUTC + TUTC_REC for delay | tUTC_DELAY | |
UTD(1) | Temp drops below TUTD for delay time | OFF | OFF | Temp rises above TUTD + TUTD_REC for delay | tUTD_DELAY |
To prevent FET damage, there are times when the CHG FET or DSG FET may be enabled even though a fault event has occurred. See the State Comparator section for details.