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Modeling >> Behavioral Models >> Problem with pole setting in verilogA
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Message started by chviswanadh on Oct 11^th, 2006, 10:23pm

Title: Problem with pole setting in verilogA
Post by chviswanadh on Oct 11^th, 2006, 10:23pm

Hello,

I am designing an OpAmp.
For setting the poles I am using Laplace_nd. I am having a problem here, for whatever pole frequency I am setting while designing, the AC simulation is giving a pole at 1/10th of the modelled pole frequency.

For example
I have set pole frequency at 2MHz in the following statement
V(vout) <+ laplace_nd((gain*V(inp,inm)), {1.0}, {1.0, 5.0e-7});

while performing AC analysis with the above I am getting a pole at 200KHz

The same way I have verified for different cases in each case it is giving 1/10th of the desired.

Am I analyzing it correct? or is it a problem with the code

Please give some inputs on this

Thanks
Chviswanadh

Title: Re: Problem with pole setting in verilogA
Post by Geoffrey_Coram on Oct 12^th, 2006, 4:30am

1/10 or 1/(2 pi) ? I believe the polynomial is in angular frequency ω = 2 π f.