• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 1 answer
  • Subscribers 47 subscribers
  • Views 910 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

OPA172: Output Protection

EE_MT
Intellectual 390 points
Part Number: OPA172

In an ESD event, what should the current be limited to for the output ESD protection circuitry? The datasheet recommends that the applications limit the input current to 10 mA, but there is no mention of the output current limitation. 

Thanks. 

  • 0
    TI__Guru 67601 points

    Matt,

    The Absolute Maximum Rated current of 10mA applies to all I/O pins, including the output, for electrical overstress (EOS) DC condition and NOT in case of ESD (few nano-second duration) event.  The EOS event occurs when you over-drive one of the I/O pins more than 0.5V beyond the rail using external source, thus forward biasing one of the ESD protection diodes located between the pin and each supply rail - see below in red boxes. ESD condition, on the other hand, does not require external current limiting and its only defined in terms of the peak voltage - see below in blue box.

  • 0 in reply to Marek Lis
    Intellectual 390 points

    Would you consider a pulse of approximately 2500V for  2ms and ESD or EOS condition?

  • 0 in reply to EE_MT
    TI__Guru 67601 points

    Matt,

    The duration of defibrillation pulse is six-orders of magnitude longer than a typical ESD pulse (few ms vs few ns, respectively) thus it should be considered a short EOS event.  Since it is not a DC condition, OPA172 should be able to tolerate significantly higher current than 10mA specified in the Absolute Maximum Ratings table - up to 100mA current pulse for up to 5ms; such condition is part of the standard latch-up test successfully performed on OPA172.  Having said that, repeated exposure of the part to such conditions may degrade device performance and/or affect its reliability.