• Resolved

UCD9090: PMBus Control Pin Configuration and Functionality

Part Number: UCD9090


We want to use CNTRL pin for Power UP/Down sequencing. I have some Query regarding this. 

1) Assume, Initially CNTRL pin is asserted and all the power rails are up. After some time, we de-assert the CNTRL pin then it start the soft power down sequencing. What will happen if during power down sequencing this CNTRL signal is again asserted? will the sequencer first complete the all power down sequencing? or it will resume the power up sequencing from that point? or any other behavior?

2) Also can we assure the power down sequencing through device reset pin?

Thanks and Regards

Tarang Jindal


  • Genius 12185 points


    #1. the power up resequence will be resume when the change of CNTRL singal is detected.

    #2.  Asserting reset pin will reset the UCD device and all IOs are set to default state simultaneously. reset pin shall not be used to power down the sequencing.



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