monte78
Junior Member
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Posts: 18

Hello everybody,
I have a question about the phy_res model in spectre. I am designing a resistive DAC using ndiffusion resistors, but I am seeing some problems about the nonlinear voltage dependence of these resistors.
In particular I noticed that the problem is due to the fact that the behaviour of the resistor is asymmetric with respect to the terminals Vt1 and Vt2, in the sense that if I put the resistors in one way I obtain a certain INL, while putting them in the opposite way the INL change (the resistor is perfectly symmetric from a layout point of view).
This is obviously a nonsense, so my questions are:
1) Can I use the phy_res model in the case that I am not sure about the more negative terminal of the resistor? 2) Why the phy_res model doesn't take into account the absolute value of the voltage across it? (polyarg=diff) 3) Is there a possibility to have the absolute value take into account on these resistors?
Thanks, Best Regards,
Monte
