Second order derivite of IV curve

[sjboy]

Hello all,

In my first assignment to Analog course, I have to plot second and third order derivitive of IV curve of NMOS transistor. I was able to do the first order rds = 1/(δId/δVds) using calculator (1/deriv(IDC("NMOS/D"))) but I'm not sure how to get the second/third order.

Any input would be appreciated,
Thanks!

 

[dedalus]

IDC returns DC operating point current (one value), so deriv(IDC(<terminal>)) should result in the error message in the CIW: can't handle deriv(<value>). You must use IS instead:

deriv(IS("/NMOS/D")) - first order derivative.
deriv(deriv(IS("/NMOS/D"))) - second order derivative.
deriv(deriv(deriv(IS("/NMOS/D")))) - third order derivative.