penghan
Member level 4
Hi, everyone
I currently simulate a 6GHz CMOS VCO by spectre.
At first, i tried to get its resonant frequency by transient simulation and fourier transform. For transient simulation of 500ns, the frequency resolution is about 2.72MHz. To achieve a resolution about 100kHz, the simulation time should be at least 10us. It will cost 10 hours or more, and is not realistic.
Then i tried pss simulation to get a more resonant frequency. I found that even no parameters or variables changed, the resonant frequency differs every simulation ±200kHz. Then, how to enhance the accuracy of pss simulation so that the frequency deviation can be minimizied within ±50kHz ? I tried to increase the stabilization time(tstab) and cut the maxstep, but they are not work. What should i do to enhance the pss simulation accuracy?
THX
I currently simulate a 6GHz CMOS VCO by spectre.
At first, i tried to get its resonant frequency by transient simulation and fourier transform. For transient simulation of 500ns, the frequency resolution is about 2.72MHz. To achieve a resolution about 100kHz, the simulation time should be at least 10us. It will cost 10 hours or more, and is not realistic.
Then i tried pss simulation to get a more resonant frequency. I found that even no parameters or variables changed, the resonant frequency differs every simulation ±200kHz. Then, how to enhance the accuracy of pss simulation so that the frequency deviation can be minimizied within ±50kHz ? I tried to increase the stabilization time(tstab) and cut the maxstep, but they are not work. What should i do to enhance the pss simulation accuracy?
THX