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DS90UB954-Q1: Function REV pin 44 - RES must be NC or tied to GND for normal operation.

Part Number: DS90UB954-Q1

Since 2017 the board was not updated and the Datasheet from 2017 was considered. As we discovered now, the datasheet from 2018 is advising to tie the RES pin 44 to GND for normal operation, not giving the option for keeping this pin floating (NC). 

Does the board need to be re-designed, with RES connected to GND? Or is it possible to keep this pin as NC? What is the risk having this pin floating?

Thanks in advance!

best regards

Michael

  • Hi Michael,

    Thanks for your inquiry. Pin 44 of the DS90UB954 is reserved with advice to pull this pin to ground to prevent the device from entering a different functional mode where the deserializer would not operate as expected. To ensure that pin 44 is held at a logical low when the device powers up, we recommend that this pin be tied to ground.

    We recommend that the application follows the latest datasheet recommendations, in this case grounding pin 44 of the DS90UB954 to ensure the device is consistently powered up into the intended functional mode.

    Best,

    Thomas