Dear all,
I'm struggling to create a noise source for the power supplies of one of my testbenches. During my online search I found out that the exact same problem was already reported in Cadence_Forum but the question got closed without any solutions and that the only user who responded is not longer a member of the forum.
Issue:
When performing a transient analysis with transient noise enabled of a single vdc source from the analog-lib with VDC = 0V and one single noise pair the average output voltage is not equal to VDC = 0V as there is a voltage jump after the first simulation step. This means at t = 0 the output voltage is at 0mV, but with the first transient simulation point the output jumps for several mV and stays at this value while the applied noise is then in the order of a few 100uV (peakToPeak). I'm even seeing a difference on the simulation time, meaning the dc offset after the first simulation step shifts with different transient simulations times.
Tried solutions:
Changing High-Performance Simulation (Spectre/APS/Spectre-X), IDC vs VDC, Covergency Aids = 0 (with are not used as there is a dc path to GND), adding a noise pair with F = 0Hz and V = 0V to remove "DC-noise"
Addon: As I'm working in a secure-net is not trivial to transfer even easy simulation results into the forum. However, the issue seen and the used setup (GND + VDC from analog-lib) is the same as in the above reported link.
Best regards
Fabian