ZHCSQB8B July 2021 – October 2022 TPS38700-Q1
In the BACKUP state only the battery is supplying power to the device, however the device must have gone through a VDD supplied state (and loaded configuration data) in order to enter this state. If no VDD supplied state has occurred, then the TPS38700-Q1 stays in the "OFF or Battery Installed" state, from which it will exit only with a valid VDD supply.
When in BACKUP state, the TPS38700-Q1 pins are in the following state:
Crystal oscillator and RTC remain active with Acc_CLK32K accuracy, but the crystal oscillator fault monitor is not active. RTC_T[31:0], interrupt, and status registers are maintained and updated. Registers configuration is maintained as set before entering the BACKUP state. PROT1 and PROT2 registers are cleared. All remaining blocks are inactive.
Upon exiting from the BACKUP state, the last configuration is active and the device enters the SHDN1 state.