the AD,PD...of BSIM3V3 mosfet in hspice

[layan]

hi every body
i use the hspice model of BSIM3V3 mosfet(0.35 um of AMS).
how can i calculate the area and premeter of drain and source(AS and AD and PD and PS) of this mosfet for using in hspice?

thanks

 

[erikl]

how can i calculate the area and premeter of drain and source(AS and AD and PD and PS) of this mosfet for using in hspice?

If you use a PDK, they will be calculated automatically during netlisting. From a layout, the physical dimensions are extracted to create the appropriate netlists for LVS and postLayout simulation.

 

[layan]

thanks but what is pdk?

 

[erikl]

thanks but what is pdk?

The Physical Design Kit (0.35 um of AMS)!

 

[layan]

yes, but sorry i didnt get the answer of my first question ?
i put here the hspice model of this mosfet here

 

[erikl]

i put here the hspice model of this mosfet here

This is publicly available material. What should we do with it?

 

[keith1200rs]

What are you using to draw the schematic and create the Spice netlist? Ideally that software would calculate AD PD etc from the design rules.

Keith

 

[layan]

no i m writing the netlist myself

 

[keith1200rs]

Ok. You will have to estimate it yourself. I presume you have the process layout rules? If you have a gds file of primitive devices that can help.

Either way, you need to find out how big the drain width and length need to be for a specific (minimum) size transistor. This could be 2um for a 0.8um process, for example. The other dimension will be the device width plus say 2um. From this you can work out ND, AD, PD etc.

For a first design pass you can omit them and just add them when you have sorted out the basic design.

I could be more specific with examples tomorrow but I am doing this on my mobile phone.

Keith

 

[rezaee]

PDK=Process Design Kit
when you write netlist you should determine L and W if your model is 0.35um then L=0.35um and W must determine with yourself and your circuit properties.

if you need you can estimate with this equations:
AD = AS = 2.5*Lmin*W
PD = PS = 5*Lmin + W or 5*Lmin

 

[keith1200rs]

Private email reply sent.

Keith.