Adding AS,AD,PS,PD to the MDAC

[Lantis]

as ad ps pd mos

I am currently designing a 10bit 37MHZ pipelined ADC.
I wonder should I add AS,AD,PS,PD in the S/H & first stage comparator,MDAC.
Any body could give me some advice?

When should I concern the mos parasitic cap of AS/AD/PS/PD ?

Thanks !

 

[Hughes]

AS,AD,PS,PD?

Adding these parameters are better than the other way.

 

[holddreams]

Re: AS,AD,PS,PD?

In a simulation spice model ,AS,AD,PS,PD almost appears.
So I think add this parameters to run simulation is closer to the final results.

 

[bastos4321]

Re: AS,AD,PS,PD?

If you do not include these parameters your simulations will not be accurate because the junction parasitics are very important in todays technologies.

Bastos

 

[ocarnu]

Re: AS,AD,PS,PD?

For an accurate simulation they are very necessary, but you don't know them before you do the layout. So, the flow IMHO is like this:
- do the simulations at the design step, but overdesign the circuit in terms of speed (20-50% more, let's say);
- try to evaluate areas and perimeters by drawing some transistors in layout, and run the simulation again with the new data.
- do the layout, extract, try again.

 

[Lantis]

AS,AD,PS,PD?

Thanks for your replys.
I try to use a tool (HSPC) which can automatic add AS/AD/PS/PD parameters.

**broken link removed**

Any comment about this tool?

Thanks!!

 

[ocarnu]

Re: AS,AD,PS,PD?

You can easly check how accurate it is by comparing the extracted value from layout with what the tool gives you.