ZHCSD75D March 2014 – January 2018
In this mode, the protector is fully powered and operational. Both CHG and DSG FETs are closed and the protector continuously checks for fault conditions.
FET enable override capability is available to the fuel gauge to force the CHG or DSG FET open based on firmware instruction. It is useful for firmware-defined safety features or other special functionality that requires one or both FETs to be opened based on specific conditions. It cannot, however, be used to enforce FET turn-on when the hardware protector is one of the protection fault modes, as the latter has ultimate authority over the FET drive control circuitry.
Firmware can also command the fuel gauge to go into SHUTDOWN mode based on a dedicated Control() subcommand from the host. In this case, firmware sets the shutdown bit, [SHUTDWN], to indicate intent to go into SHUTDOWN mode. The fuel gauge then transitions to SHUTDOWN WAIT mode and waits for charger removal prior to disabling the internal LDO and fully powering down the entire device.