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Design >> Mixed-Signal Design >> Switch model in ADC sim
https://designers-guide.org/forum/YaBB.pl?num=1106786076

Message started by maserati on Jan 26^th, 2005, 4:34pm

Title: Switch model in ADC sim
Post by maserati on Jan 26^th, 2005, 4:34pm

I am designing a SAR (successive appox. register) ADC, and I want to model and simulate the circuit with some ideal components first.
Which cell should I use from analogLib? I tried to use "vcres" to sim, but it cannot edit its properties.
I was using Cadence 5.0.3.3
by the way, I found Cadence 5.1.4.1 lacks of "vcres" properties file either. I'm wondering if there is a bug from Cadence.

So, which components should I use to model a ideal switch?

Title: Re: Switch model in ADC sim
Post by codec on Jan 28^th, 2005, 8:30pm

Hi, Maserati
You can use 'Relay' in analogLib. It is similar to Gxxx in HSPICE.

Title: Re: Switch model in ADC sim
Post by sheldon on Mar 7^th, 2005, 6:57pm

Greetings,

If you have access to AMS Designer, there is a switch behavioral model
in bmslib. IThe switch is modeled as a variable reisistance and in general
performs well in simulations, i.e., the transfer function is smooth and
continuous.

Best Regards,

Sheldon

Title: Re: Switch model in ADC sim
Post by Andrew Beckett on Mar 8^th, 2005, 1:22am

A reply to the orginal post. vcres is only for HSPICE, if my memory serves. It always has been. You're probably not seeing the parameters as I think it doesn't show hspice-related parameters by defaults (use Options->Parameter Filter or whatever the menu is called in the schematic editor).

You should be able to use vccs in recent versions as a voltage controlled resistor in spectre - or you can use relay as suggested.

Andrew.