In cadence, how to add clock signal in oscillator circuit and do the simulation?

[diego.fan]

Hi, all

I wanna add a clock signal using "vpulse" in vco circuit. When I run 'pss'. It will show this error.

Error found by spectre during periodic steady state analysis `pss'.
ERROR (CMI-2208): `V3' is a periodic input signal, which is inconsistent with autonomous circuits.
Warning from spectre during periodic steady state analysis `pss'.
WARNING (SPECTRE-16518): Arithmetic exception in analysis `pss' .

Analysis `pss' was terminated prematurely due to an error.
modelParameter: writing model parameter values to rawfile.

It seems oscillators circuit cannot work together with clock signal.

Do you know how to fix it? Thanks

 

[frankrose]

VCO's frequency never will be in phase with your clock's fundamental frequency. It is natural I think it can't find a soulution. Use simple transient to check step response, use DFT to see the spectrum. You can use pss to see its output distortion on a fix input voltage but that is all.

 

[BigBoss]

If you have placed this Vpulse source to trig the VCO, it won't work.You should use Vpwl source to excite the VCO.

 

[pancho_hideboo]

Use semi-autonomous QPSS analysis.

 

[diego.fan]

Thanks! May I ask where to find the detailed help document of semi-autonomous QPSS analysis?

 

[pancho_hideboo]

May I ask where to find the detailed help document of semi-autonomous QPSS analysis?

%spectre -h qpss
%spectre -h hb

See https://www.edaboard.com/showthread.php?378469#6