2.4.5 Enable Timeout Delay (t8) and Enable Interrupt Assertion Timeout Delay (t9) Programming Bits

Table 2-3. Enable Timeout Delay Bits ENTO[1:0] and Enable Interrupt Assertion Timeout Delay Bits ENINTTO[1:0]
ENTO[1:0]Enable timeout delay t8 (s) ENINTTO[1:0]Enable interrupt assertion timeout delay t9 (s)
000000.1
012010.5
104101
118112

During runtime (when PWRHLD = 1), it is possible for the EN input to go LOW first, followed by the MPU setting PWRHLD to LOW before the expiration of t8 + t9. In this scenario, the steady EN = LOW condition does not trigger an automatic restart action.

If PWRHLD goes LOW during runtime, that means the MPU software has decided to go to OFF/HIBERNATE (by deasserting SHDN from the SHDWC Controller) regardless of the nSTRTO pin status (which is also monitored in the SHDWC controller).

Therefore, the MCP16503 will attempt a new start-up only when PWRHLD transitions from Low to High, while also keeping the EN = High.