• State Resolved
  • Locked Locked
  • Replies 5 replies
  • Subscribers 50 subscribers
  • Views 565 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.

OPA130 Single supply?

John Vranes
Intellectual 590 points
Other Parts Discussed in Thread: OPA130

Can OPA130 be powered by a single ended supply (i.e., V- = 0V, V+ = 36 V max), as long as the specified input common mode range is satisfied?

Thanks

  • 0
    TI__Expert 3555 points

    John,

    Ues the OPA130 can be power by this type of single supply. As you mention becareful of the input common mode range (which would be +2V to VCC - 2V {max}}  and pay attention to the output swing restrictions in the data sheet.

  • 0
    TI__Guru 60610 points

    John,

    Since there is no internal ground inside the op amps, ALL of them can be used in a single, dual, or asymmetric supply configuration AS LONG AS the input common-mode voltage AND the output voltage range specified with respect to rails is NOT violated.

  • 0 in reply to Bonnie Baker - WEBENCH Design Center
    Intellectual 590 points

    Thanks, Bonnie and Marek).

    If I may follow up - what are the consequences of violating the input common mode or output range?  Does it damage the part?  Output falls to zero (or something of that nature)?  Output gets clipped?  Or is that behavior simply undefined when those two criteria are violated?

    Thanks,

    John

  • 0 in reply to John Vranes
    Expert 1095 points

    Hi John Vranes,

       Answer for your question is in this video made by TI. https://www.youtube.com/watch?v=h7pezlnr1V8

  • 0 in reply to John Vranes
    TI__Expert 3555 points

    John,

    The two issues are the input voltage limits and the output swing.

    With the input voltage, you can refer to the absolute maximum ratings in the data sheet. For the OPA130 these ratings are:

    Input Voltage ..................................................... (V–) – 0.7V to (V+) +0.7V

    If you exceed these limits it is possible that can damage the input transistors. You may notice that the specification is 0.7 V which is precisely the forward voltage that you would expect from a silicon p-n junction. This is not a coincidence. Internal to the input stage of the OPA130 there are ESD diodes. As your input voltages approaches these limits you will start to see an increase in input bias current. If this input bias current becomes high enough, it will overheat the chip and cause permanent damage.

    The other issue is the output stage. Assuming you are not driving the output stage externally to a particular voltage, an output overvoltage signal will be clamped by the output stage transistors.

    John is correct about the video. Watch it an enjoy.