Regardless of which EMSHUT entry method is used, the gauge can exit the EMSHUT mode by turning on the CHG and DSG FETs with any one of the following conditions:
- A high-to-low transition on the
SHUTDN pin is detected with a debounce delay of 1 s for the low level threshold. For example, a push button is pressed again. This exit condition can be disabled by setting the [EMSHUT_PEXIT_DIS] bit in the DA Configuration register.
- Send word 0x23A7 to ManufacturerAccess() (0x00).
- PACK voltage > Charger Present Threshold for two sample periods (that is, ~500 ms). This exit condition requires the [EMSHUT_EXIT_VPACK] bit to be set.
- Valid SMBus communication is received. Valid SMBus communication means a valid gauge address and any command is received (that is, an invalid command with a valid address is OK). This exit condition requires the [EMSHUT_EXIT_COMM] bit to be set. When using this exit option, the Manual FET Control (MFC) Delay should be set to a minimum of 4 seconds.
In addition to these exit conditions, if the gauge enters EMSHUT (via a push button, for example), it can exit the EMSHUT mode after a shutdown restore timeout defined by the Timeout parameter. When the timeout is equal to 0, it will not exit EMSHUT mode.
For the case of [NR] = 0, a battery insertion will also exit the EMERGENCY FET SHUTDOWN mode.
In EMSHUT mode, to detect the voltage level at the PACK pin quickly (even while in SLEEP), the AD conversion will occur every second.