ZHCSKK3B December 2019 – February 2022 TPS6594-Q1
PRODUCTION DATA
The LDOVRTC is supplied from either the VBACKUP (backup supply from either coin-cell or super-cap) input or VCCA. The power-path is designed to prioritize VCCA to maximize the life of the backup supply.
When VCCA drops below the VCCA_UVLO threshold, the device shuts down all rails except the LDOVRTC, and enters the BACKUP mode. At this point, the Backup Supply Power-Path switches to the VBACKUP as the input of LDOVRTC. When the voltage of VCCA returns to level above the VCCA_UVLO threshold level, the power-path switches the input of LDOVRTC back to VCCA.
When both the VCCA voltage drop below the VCCA_UVLO threshold, and the VBACKUP voltage drops below 1.7V (RTC_LDO_UVLO threshold), the LDOVRTC is turned OFF and the digital core is reset, which forces the device into the NO SUPPLY state.
Note: a backup supply is not required for the device to operate. The device skips the BACKUP state if the VBACKUP pin is grounded.