• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 48 subscribers
  • Views 46 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

OPA4H199-SEP: Cold Sparing of OPA4H199-SEP

Jash Kothari
Prodigy 380 points
Part Number: OPA4H199-SEP

Tool/software:

Hi Team,

My customer wants to use the OPA4H199-SEP for their space application. Since they would have inputs going to the main and redundant cards at all the times but the VDD would only be in the main card, they want to check if the device can withstand cold sparing - basically can the device withstand an active input signal on the INx+/- even when the VDD = 0V condition. Let me know the same.

Thanks,

Jash 

  • 0
    TI__Mastermind 25911 points

    Hey Jash,

    Yes, the device can withstand an input without supply voltage, but only under specific conditions.

    1. The supply pin must be able to sink current
    2. The input voltage must not generate a current through the input above 10mA (<1mA preferred)

    The reason for this is that the internal ESD diodes can sink a small amount of current, and therefore it is ok to have an input voltage without a supply voltage. Please see the below screenshot from the datasheet. Everything inside the dotted line box is internal to the amplifier. If your supply is high impedance, a zener TVS diode can be added to the supply pin to sink current in case of an overvoltage event on the inputs.

    Best,
    Jerry