"Weird" result in MOSFET Capacitance calculation.

[Sant0z]

Hi everyone,

I have a problem with the simulation result for calculating N-CH Mosfet capacitance (Cgs, Cgd, and Cdb).  

In this simulation I tried to verify my manual calculation with the Spice result using Multsim 11.0. But, the result in Multism simulation is quit different either from the manual calculation or from Pspice/Hspice simulation.

Manual Calculation:

Multisim Simulation:

Setting Parameters in Multisim:

.DC from Multisim

>DC from PSPICE

From those results, it seems that Pspice gave a close value to the theoretical MOSFET calculation here.  And I got messy result in Multisim.

Can somebody help me solving this problem?..is Multisim not as powerful as other spice software? or I just messed up with the parameters setting form Multisim and ended with the wrong answer?

[ajmartin]

You need to post this on the Multisim forum.

Alan