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OPA548: max continuous and peak currents that may be sourced from or sunk into the inverting input terminal

Nitish Agrawal
Expert 1585 points
Part Number: OPA548

What are the maximum conitnuous and peak currents that be sourced from or sunk into the inverting input terminal of OPA548?

Kind regards,

Nitish Agrawal

  • 0
    Guru 140200 points

    Hi Nitish,

    if it's not specified in the datasheet, I would keep the input current significantly under 1mA. But I say this without giving any guarantee!

    The best way would be to use a protection circuit with a diode clamp which prevents the input voltage from exceeding the supply voltages.

    Can you show a schematic of your circuit?

    Kai

  • 0
    Guru 48395 points

    That sort of question only makes sense as sort of a fault condition. If you open the loop and force the V- pin outside the rails the ESD steering diodes will indeed turn on - however, in normal op amp configurations the Rg and Rf resistors will limit that current flow. 

    A lot of times that overdrive current through the ESD diodes is specified as max 10mA. Have to have some number but it is a bit of a handwave. 

  • 0
    TI__Genius 10625 points

    Nitish,

    As other community members have pointed out, a range of -10mA to 10mA can typically be sourced or sunk from either input terminal in an open loop condition. Often the exact value is not specified in the data sheet for older parts such as the OPA548. In this case limiting the current to +/-1mA is the safest option if application can tolerate it.

    Zach Olson