how to simulate VCO F-V curve?

[mdcui]

I am trying to design a VCO, to characterize the gain, i.e. d(freq)/d(Vctrl). A frequency vs control voltage plot is necessary, however I do not know with HSPICE/ELDO simulator and spice explorer waveform viewer, how I can plot this curve?

thanks a lot.

 

[V_D_R]

note down frequency at different voltages and tabulate in exel sheet. In exel plot freq. v/s voltage
and you can find slope of the curve (i.e., d(freq)/dv --- gain of VCO )

and you use any script such as Ocean or Pearl to note down frequency at different voltages and to tabulate in exel sheet

 

[mzhanghong]

In Hspice ,you can use .data description to alter the simulation at different control volage.
then use a .measure to calculate the frequency at each control voltage in the .data description.
after that, plot a f-v curve is easy.

 

[neoflash]

You can use .meas to calculate the fosc in transient simulation.

and then use

.tran 2p 10n sweep vc 0 1 0.01

to get multiple measurements, eldo will give you a .sw0 file which contains swept measurement results.

 

[khouly]

if u have ELDO RF , u can use the SST comand too simulate the frequency versus voltage

Khouly

 

[lisamoni]

hi
how i can use .meas to calculate fosc??please help me.i can not find frea vs cont voltage curve