Part Number:OPA657
Tool/software:TINA-TI or Spice Models
I'm having issues with the OPA657 Rev. E model in LTspice. I'm using the amplifier model as my op-amp in a transimpedance amplifier circuit shown below:
I first downloaded the PSPICE model from TI's website, and in LTspice, I opened up the file 'OPA657.lib'. I then highlighted the part name in the '.subckt' definition at the beginning of the file, and created a symbol from it after right clicking on the name. Once I created the part symbol, I inserted it into my schematic as shown above, and I ran a simulation of the circuit for 1 microsecond. However, there were some issues that came up in the simulation that prevented it from being completed. You can see them in the images below:
In the first picture, the simulation stopped at 400 nanoseconds. Having the simulation stop here gives some really unrealistic results as shown below:
Somehow, the op-amp gives out really unrealistic voltages. For instance, at the output, it went as low as -1e18 V.
I tried this with several other amplifier models, using the method above to import them into LTspice and creating symbols from them, and they all worked fine. I even tried this with the OPA656 amplifier from TI, and there were no problems with it. I think there might be something wrong in the PSPICE model for the OPA657 that's causing this issue in LTspice.