7.5.3 CLEAR_FAULTS (03h)
The CLEAR_FAULTS command is used to clear any fault bits that have been set. This command clears all bits in all status registers simultaneously. At the same time, the device negates (clears, releases) its SMBALERT signal output if the device is asserting the SMBALERT signal. The CLEAR_FAULTS command does not cause a unit that has latched off for a fault condition to restart. If the fault is still present when the bit is cleared, the fault bit is immediately reset and the host notified by the usual means.
- To get a reliable clear fault result, the clear_fault command should be issued (8 × TON_RISE + TON_DELAY) after the switcher shuts down.
- In the case of OV fault with a latch off response, the LS FET latches on when the fault is detected. If the OV_RESP_SEL Bit in (F0h) MFR_SPECIFIC_32 is set to 1, then the LS FET releases when the FB pin voltage falls below 0.2 V. Otherwise, it remains on until the CLEAR_FAULTS command is issued. The CLEAR FAULTS command causes the LS FET to turn off.
- CNTL pin toggling can also clear fault, but the logic low duration should be higher than 100 ns for the internal circuit to recognize.