Paul van Zeijl

Marcel, Yes, there are limitation to pss-pac-pnoise (you need pnoise for pss). Paul

Marcel, on the motivation: I prefer to have PSS, PAC, PNOISE analysis for analysing mixer/transmitter/receiver circuits. I have seen NGSPICE-PSS work work but only for oscillators. I would be nice to have it work at fixed frequencies (which I expect to be easier than non-fixed, not-know frequencies). But PSS-PAC-PNOISE cannot be used in PLLs, delta-sigma modulators and detecting PRBS sequences, as they don't have a steady-state solution. I expect the TRNOISE to be implemented easier, although simulator...

Marcel, you say "I can't say with confidence that the tran noise code is bugfree". I think you mean to say that " I can say ...", right? I agree with that the noise amplitude in the time-domain is correct. In the frequency domain I found that pending window function the (low-frequency) noise-amplitude (in dB/sqrt(Hz)) may vary some dB's. I will check the exact relation later. What do you think on extending the ngspice functionality with generation noise for all resistors and active devices? regards,...

Marcel, I remember simulating without re-sampling using trnoise(1, 1e-6, ...) giving 0.85 as rms voltages, which corresponds to your trnoise(sqrt(2)=1.4, 1e-6 ..) giving 1.2. When I resample the output data at 1/fs=1us multiples (actually only taking the values at multiples of 1 us), I get an rms-values of 1.0 with deviations of +/-3% max (up to 100 runs averaged), also for repeated runs. So the generation of the random variable is ok. My interest is into mainly in frequency domain results, that's...

Dietmar, I confirm that the {} brackets solves the problem. Indeed the .end statement was missing, but I did not get an error. Thanks for filing the ticket. regards, Paul

transient noise extension