This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPS54218: Supplying voltage on output

Part Number: TPS54218

Hi Team,

I received a question from customer where they are using the TPS54218 for 3.3V output. They were asking if there is any issue to supply a 3.3V on the output while the device is not supplied with any voltage? Will it cause any problems with the IC? Based on my understanding, there will be no issue but I just wanted to double check with you all just to make sure.

Thanks! 

BR,

Alfred

  • Alfred,

    There are two thing s to be concerned with:
    1. With 3.3 V pre-piased output, there is a leakage path thru the high side switch body diode back to VIN. So you will have about 2.7 V on the input. That may be above the UVLO for VIN. You should ensure EN is held low during that time.
    2. TPS54218 does not have any pre-bias start up feature. The output will be discharged thru the low side switch before the output ramps up to regulation at start up.