SLVUCI2 march 2023 AM68A , AM69 , AM69A , TDA4AH-Q1 , TDA4AL-Q1 , TDA4AP-Q1 , TDA4VE-Q1 , TDA4VH-Q1 , TDA4VL-Q1 , TDA4VP-Q1 , TPS6594-Q1
The TO_SAFE_SEVERE and TO_SAFE are distinct sequences that occur before transitioning to the SAFE state. Both sequences shut down all rails without delay. The TO_SAFE_SEVERE sequence immediately ceases BUCK switching and enables the pulldown resistors of the BUCKs and LDOs. The objective of the TO_SAFE_SEVERE sequence is to prevent any damage to the PMIC in case of over voltage on VCCA or thermal shutdown. The timing is illustrated in Figure 5-2. The TO_SAFE sequence does not reset the BUCK regulators until after the regulators are turned off.
TO_SAFE sequence delays the TPS6594133A by 16 ms. The delay ensures that the PMIC finishes after . After these delays, the following instructions are executed on the PMIC:
After the power sequence shown in Figure 5-2, the TO_SAFE_SEVERE sequence executes the following instructions:
// TPS6594133A
// Clear AMUXOUT_EN
REG_WRITE_MASK_IMM ADDR=0x81 DATA=0x00 MASK=0xEF
The TPS6594133A has an
additional delay of 500 ms at the end of the TO_SAFE_SEVERE sequence. It is
important to note that the recovery is not attempted until after the sequence delay
is complete.