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OPA695: Output over range recovery time

Part Number: OPA695


Our customer has a question about output over range recovery time.

I think this spec is Figure 23 (P15).

 How can we understand the recovery time?

Our customer setup
/ Vs = +/-5V
/ gain = 2.5
/ 1V/1us input pulse with +1V overshoot
/ overshoot = 30ns

It will not saturate if the common mode input range is lowered.
However, they want to saturate on purpose because they want to increase the input range for the ADC.
Because overshoot is unnecessary...
And since the necessary waveform is lost, the filter can not be inserted either, and they expect a recover within 30ns..
Best regards,


  • Hello Hiroshi,

    Little hard to follow what you are describing, but - anything that causes the loop to open up transiently gets into an unspecified recovery time and settling to final value. those include,

    1. if you slew limit on the transition, that opens the loop and you will a non-linear recovery time - not specified
    2. if your output overshoot goes into the max output swing range, the loop will open and the non-linear recovery time is not specified

    That Figure23 was mainly intended to show there was no phase reversal on overdrive - not specifically how fast it comes out of overdrive,

    And note your gain of 2.5 will have varying response shapes and its own overshoot depending on the Rf value.

    A TINA file and input waveform would help.
  • Hi Hiroshi,

    figure 23 and 24 show the overdrive recovery behaviour at a gain of +8 and -8. At a gain of 2.5, on the other hand, the overdrive recovery might look a bit different. So, I would do own measurements.

  • Hi, Michael, Kai,

    Thank you for your reply.
    I also try with Tina and the evaluation board.

    Best regards,
  • TINA will not model overdrive recovery time - again, that is normally maybe a typ only spec with no guarantees - years ago we tried to provide a spec, but it varied a lot by external circuit and part to part - if you need a more defined clipping and recovery operation, look at the OPA688
  • Hi Hiroshi,

    TINA might not properly simulate the overdrive recovery performance of OPA695, as spice models are rather limited when it comes to untypical operating conditions.

  • Hi all,

    Thank you for your advice.
    I understood you.

    Best regards,