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LM5164-Q1: Redundant Regulator Configuration

Part Number: LM5164-Q1
Other Parts Discussed in Thread: LM5165, LM5164

Tool/software:

Dear Forum:

I have a application that requires improved reliability for a main power rail.  In my example below, I am using two LM5165 wide-rage buck converters to generate a nominal 3.3V @ 500mA.  The idea of this configuration is that each regulator's control loop servos the output voltage to be close to the nominal output voltage target of 3.3V.  From my understanding, since each loop has its own divider and 1.2V reference, identical voltage regulation is not possible but the ORing Schottky diodes will absorb the small differential and the final output voltage should be close to the target and the load current split roughly equally.   Is this dual regulator configuration valid?

In a fault condition, where one buck converter fails, the other regulator should be able to take over and regulate.  The ORing diodes should protect against a failure of the output switch opening.  However,  is there a failure mechanism that could result in the input 28V rail being driven to the switch terminal and through the output inductor?  If so is an OVP crowbar required for each regulator before the ORing didodes?

If there is a better way to provide redundancy please let me know.

Best,

Craig