[SOLVED] ron vs. output resistance

[fuxinmingming]

Hi guys,

I simulated the output resistance of MOSFET using TSMC018mm technology. I sweep Vds and use calculator to draw the output resistance vs. Vds. However, the curve is different with the DC operating point I print.

Here is the detail:

I set Vgs=Vds=1V, Vsb=0. Then I simulate and print the DC operating point to get ron. The pring result is:

ron=63k

However, from the output resistance curve(obtained by calculator) is 8.9M.

My question is:

1. Is ron(printed in the DC operating) the output resistance of MOSFET?
2. Why ron is different from the result obtained by calculator?

Regards,

Ming

 

[checkmate]

1. Is ron(printed in the DC operating) the output resistance of MOSFET?

No. Enough said for the rest.
You should get your definitions right first before proceeding with analysis.

 

[kishore2k4]

The small signal output resistance is 1/gds. Get the gds value from the DC OP.

 

[fuxinmingming]

Hi kish,

thank you very much.