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OPA837: spice model input bias current

Part Number: OPA837

Hello, 

Are the input bias currents modeled in the OPA837 spice model? According to the notes in the model, the bias currents should be modeled.

However, the simulation shows bias currents of ~17uA. According to the datasheet the bias currents should be ~300nA. 

Am I missing something? 

Thank you in advance,

Alex. 

  • There is a 2nd subckt in the netlist for this that maybe should have been removed, This is in the August 2018 model update, 

    I went back to a 2016 version and the magnitudes are closer, but the current should be coming out of the nodes (pnp inputs) and these are reversed actually - 

  • Hello Michael, 

    How do you suggest to proceed?

    The model is not very usable due to offset voltages caused by the bias currents. Can I just remove the 2nd .SUBCKT from the current model? Can you release an updated model? 

    Thanks again. 

  • Well what I have done in the past is add external current sources to make the net correct. Little dicey changing the netlist as there are often hard to follow interactions. 

    I was able to flip the polarity in that 2016 model, you want that one modified

  • Here is the closest to release model I can find, with the Ib and Ios magnitudes right and polarity flipped on the Ib, 

    Note all theses DC things are typs in the model with quite a physical spread around those. 

    OPA837prelimRev3 modified Ib July2020.TSC