Hi all,

I have a general question about simulating circuits with a manufacture spice model.

I am simulating my design for a 24v to 5v Buck using a TI model (TPS54308) in TINA TI (its a TI model so i cant use Ltspice).
I know about Pspice-for-TI but the simulator gives very strange output when compared to TINA TI or just Pspice using the same components...

but in each software i tried, it took ages for each simulation to run (i am simulating Transient - 15ms Run and it takes about 40-60 minutes to finish)

when i looked at the processes tab I've seen that CPU is at 67% usage and the GPU is 0%.

my question is [had to give a little brief before, sorry ] which PC part takes the most stress during the simulations... an upgrade is in the near future anyway..
thanks

 

That's going to depend heavily on how they compiled that specific version of the simulator. It looks like yours was compiled so as to not leverage the GPU (since some people may not have one), or the code was written in such a way that the compiler couldn't figure out a way to utilize it.

Simulations can take a long time to run. They can use a lot of memory, so having lots of memory and have it configured so that it can be used efficiently will help out a lot. Other than that, there are often setting in the simulator controlling things like timestep resolution, convergence requirements, integration methods, and so forth that can make a big difference in how long a simulation runs -- be be prepared for a tradeoff between runtime and fidelity of the results.

 

Simulating switching circuits, such as buck regulators, generally have a long run-time, since many cycles of the switching frequency need to be simulated, even for a short real-time period.
For example, 15ms of run time for the TPS54308 converter running at 350kHz, requires the computation of over 5000 complete cycles of the IC operation.
Given that each cycle likely requires thousands of iterative, high-precision floating-point Spice calculations, you can see how that can require a long run-time.