OP4177 opamp is not working as voltage limiter.

Hi!

I am facing some issues with OP4177 (precision amplifier)  in a voltage limiting application. Earlier in the design LM-148 ( quad uA741) was used and there was absolutely no issue. In the same configuration OP4177 gives horrible results with absolutely no clue.

Am attaching the circuit and practical results for reference.

Please advice.

Regards

Ruchi

attachments.zip
  • Hello Harry!

    I selected OP4177 as a replacement for LM148 in my design based on the specs given in datasheet. I found it better in every aspect e.g. offset, bias current, supply current. Slew rate , gain BW were comparable too.

    Now when it is not working in my final board, I am in a fix. Even if I try to choose another opamp now, I really do not know which parameter to look for in the datasheet to ensure that the problem does not repeat.

    reason for changing LM148 was its non-availability in SOIC package with +125degC operating temp range which is required in my application.

    Ruchi

  • Thanks Harry!

    I would try for other opamps too as suggested. I am also working on alternative configurations for the voltage limiter

    circuit with the same OP4177 . Have you come across any alternate configuration for such application which you would like to suggest?

    Regards

    Ruchi