AD633 square root - Pspice simulation

Discussion in 'Homework Help' started by malincik, Apr 29, 2012.

  1. malincik

    Thread Starter New Member

    Apr 29, 2012
    Hello gentlemen (and ladies :) )
    I have a problem with simulation in PSpice, I use student version Cadence 16.2
    I have to simulate a square root using IC AD633. This is my netlist:
    The netlist is the exact copy of Root Square from AD633 datasheet, Figure 14. ( here )

    There is an ideal plot of root square using E type source, the green trace in the picture
    The output trace of circuit is the red one and it is very far from square root :D

    Libraries of AD633and AD711 are these : ,

    I tried to use different opamp model (ua741 written), no difference. Well, I tried to simulate Division, but there was a similar problem, strange plot of it. I think there is a problem with AD633 put in loopback of the opamp.
    Simulation in OrCAD 9.1 student version crashes with DC convergence problem.

    Can you please help me ? Thank you