The TPS7H3014
incorporates a comprehensive state machine engine. Three possible outcomes are
possible depending on the detected inputs states.
- A reverse sequence down from
previously deemed-good (forced high) ENx signals, is started if:
- VOUTx fails to
reach the VONx voltage during sequence up within the time
establish by the REG_TMR, when ENx is high.
- Any VOUTx
crosses the VOFFx after previously crossing the
VONx and the VOUTx+1 has not yet crossed the
VONx+1.
- The users command a
sequence down in the middle of a sequence up.
- All outputs (ENx, SEQ_DONE and
PWRGD) are forced low if an out-of-order is detected, this means:
- A previously deemed-good
rail VOUTx drops below VOFFx when at least the
VOUTx+1 is already in regulation (deemed-good).
- Any VOUTx >
VONx when ENX is not high. Valid only
during sequence up.
Note:
It is typical in
sequencers to set VONx as some percentage of the
nominal voltage to be monitored (E.g. VONx = 0.8 ×
VOUTx). There is a period of time during sequence
down at which the VOUTx ≥ VONx. As the
discharge rate of the rail (VOUTx) is unknown to the
TPS7H3014, this feature is only valid during sequence up.
- A sequence up from previously
forced low ENx signals, after the DLY_TMR is expired is started if:
- The users command a
sequence up in the middle of a sequence down.
Figure 8-14 TPS7H3014 State Machine
Diagram