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Analog Verification >> Analog Performance Verification >> adexl conditional specifications
https://designers-guide.org/forum/YaBB.pl?num=1428092749

Message started by danmc on Apr 3^rd, 2015, 1:25pm

Title: adexl conditional specifications
Post by danmc on Apr 3^rd, 2015, 1:25pm

I'm having troubles writing conditional specifications in ADE-XL and am wondering if anyone has good suggestions. Here is a simple example:

circuit: tunable lowpass filter
simulation: ac sim that measured -3 dB bandwidth
parameters: frequency control, PVT

so what I want is to run a bunch of simulations over PVT and with the frequency control at min and at max. My specs would be then:

BW_sim@control=min < minimum bandwidth spec
BW_sim@control=max > maximum bandwidth spec

In other words, the sim looks over PVT and makes sure the desired range of bandwidths is achievable over all PVT.

I don't know how to make the measurement in ADE-XL depend on the frequency control parameter.

Thanks
-Dan

Title: Re: adexl conditional specifications
Post by weber8722 on Apr 21^st, 2015, 11:34pm

Hi,

I think two approaches are the simplest in ADEXL:

1. Use of variables like VGainSetting and use of VAR("VGainSetting") in the output equations. Run eg. an AC sweep at fix freq (like 100MHz) and sweep this variable. With value(VF(out) ...) you can pick the desired gain

or

2. Make just two tests: One for low-gain and a 2nd for high-gain.

Also corner-specific specs are possible using "spec-overridings".

Bye Stephan