• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Subscribers 50 subscribers
  • Views 220 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.

OPA314: Will this circuit be susceptible to oscillations?

Darren (FAE)
Expert 5483 points
Part Number: OPA314
Other Parts Discussed in Thread: ADS1015,

I have a question on the stability of a design using the OPA314 and ADS1015.
There will be a differential signal to the OPA314 inputs, and the output will go to ADS1015.

Schematic

Do you see any concerns with this circuit?

  • 0
    Guru 140200 points

    Hi Darren,

    I cannot open the link.

    Kai

  • +1
    TI__Guru*** 140106 points

    Hello Darren,

    Zero chance of oscillation. The bandwidth is 100Hz, was that intentional?

  • Former Member
    +1 Former Member

    Hi Darren,

    I ran a quick stability simulation and you should be fine with around 72° of phase margin.  The isolation resistor will stabilize your circuit.  I do wonder why the customer wants to use such a large load/charge kick back capacitor.

    The input impedance of the ADS1015 is not well-defined in the data sheet, but seems inconsequential especially given the load you have placed on the output.  I would say, I am not sure if that 12kΩ resistor is actually supposed to be 12.4kΩ.  Seems like that is a possible typo.

    Let me know if you need any further help.

    Regards,
    Daniel