Phase-locked loops have the exact same problem. If your Spice engine is doing its matrix math every 20 nanoseconds, than means it will take a long long time to solve the circuit. It may take milliseconds or even seconds for the circuit to come up to its final steady-state operation.
I thought it was because of the problems simulating magnetics, but there is another fundamental problem. Power converters are notoriously hard to simulate. See, LT is famous for their power converters. A buddy that retired from Linear Technology explained why Mike Engelhardt was so brilliant when he developed LT’s free LTSpice. I have learned a few things about Spice lately. And no, this does not help simulate 1/f noise, that is a whole ‘nuther problem. Taking the integral of the ABS of the noise spectrum did the trick.
I know the RMS noise could not be going down over bandwidth like PSpice was showing, but darned if I could have figured it out. I will always respect Cano for figuring that out. Trick is the signal is complex, so you have to take the nV/rtHz results and take the absolute value first before you integrate it to get uV of RMS noise over a bandwidth. He was the one that helped me simulate op-amp noise with signal generators. My buddy Martin Cano over at Agilent is buying the paid-for version of Tina-Spice and I will let you know how he likes it. Virtual instruments allow users to select input waveforms and probe circuit node voltages and waveforms. TINA-TI 9.1 provides all the conventional DC, transient and frequency domain analysis of SPICE and extensive post-processing capability that allows the user to customize results.The broad model coverage and fast simulation in TINA-TI 9.1 make it easier for designers to speed their products to market. TINA-TI 9.1 will feature more than 500 part models and reference designs including more than 130 new power models.Designers can import any SPICE model to easily simulate their designs in TINA-TI 9.1.Support for multi-core processors and an optimized SPICE engine enable TINA-TI 9.1 to run simulations 5X faster on average.It is available in simplified and traditional Chinese, Japanese and Russian, as well as English. I got a nice note from the irrepressible Mary Dunnie that Texas Instruments has improved its Tina-TI Spice tool.
0 kommentar(er)
