Simulating a varactor in spectre

[Maz]

Hi, I am trying to simulate a basic varactor in spectre. I am doing a
transient analysis on a varactor, however, I am only seeing a linear
voltage, rather than the charging characteristics that one would see
for a regular capacitor.

Does anyone know how to plot the control voltage vs the capacitance of
a varactor using spectre.

Thanks.

 

[Erik Wanta]

See http://www.designers-guide.org/Modeling/varactors.pdf
---
Erik

 

[Andrew Beckett]

On 18 Feb 2006 15:43:31 -0800, "Maz" <maz.khorasani@gmail.com> wrote:

Hi, I am trying to simulate a basic varactor in spectre. I am doing a
transient analysis on a varactor, however, I am only seeing a linear
voltage, rather than the charging characteristics that one would see
for a regular capacitor.

Does anyone know how to plot the control voltage vs the capacitance of
a varactor using spectre.

Thanks.

Well, without having some knowledge of how the varactor is implemented, it's
hard to answer this.

I would imagine that you could integrate the current through the capacitor, and
divide by the voltage across it - and then plot that against the control
voltage? (Plot both the first calculation, and the control voltage, and then
change the X axis to be the control voltage).

Regards,

Andrew.