Stats

  • State Not Answered
  • Replies 3
  • Subscribers 28
  • Views 345
  • Members are here 0
More Content

LMR51625Y Buck converter simulation Too slow

SS202602185019

"Hey, I’m running a simulation with the attached circuit and config, but it’s running incredibly slow. I’ve set the Run To Time to 50ms with a Maximum Step Size of 100ns. That’s 500,000 steps minimum, and it's taking forever. Does the step size need to be this granular, or is there something in the circuit causing a convergence bottleneck?""Hey, I’m running a simulation with the attached circuit and config, but it’s running incredibly slow. I’ve set the Run To Time to 50ms with a Maximum Step Size of 100ns. That’s 500,000 steps minimum, and it's taking forever. Does the step size need to be this granular, or is there something in the circuit causing a convergence bottleneck?"  , This simulation is after 5 Minutes

Parents
  • oldmouldy
    0

    The provided TI sample has a 4.5ms end time and takes around 20 minutes to run for me. You are running for twice that time so you could expect, at least, around double that for your simulation. A simulation with a transient model evaluates every cycle of the circuit in detail, that will never be "fast" for a switched mode controller like this. PSpice will attempt to find the optimum step size dynamically; the Maximum Step Size forces PSpice to evaluate the circuit, even if the dynamic step size doesn't schedule an evaluation. This can improve the resolution of the output. Transient models like this are only ever usable for investigating startup conditions, they are impractical to use for any load testing for which "state averaging" models are required.

  • SS202602185019
    0 in reply to oldmouldy

    Okay it takes 6 Hours to complete the simulation With adding 3 value to analysis in PArameter sweep so Its okay if it takes that amount of time but Can u little explain why the simulation of circuit is impractical for load testing?

Reply
  • SS202602185019
    0 in reply to oldmouldy

    Okay it takes 6 Hours to complete the simulation With adding 3 value to analysis in PArameter sweep so Its okay if it takes that amount of time but Can u little explain why the simulation of circuit is impractical for load testing?

Children
  • IshaS
    0 in reply to SS202602185019

    Your controller switches at:

    • 100 kHz → 10 µs switching period
    • Over 50 ms of runtime → 5,000 switching cycles
    • With a 100 ns max timestep → 100 steps per switching cycle

    This means:
    100 steps × 5,000 cycles = 500,000 steps minimum

    Can you confirm if your circuit is simulating like this?

    It seems slowness is coming due to nature of the circuit. not just the timestep

Cadence Guidelines

Community Guidelines

The Cadence Design Communities support Cadence users and technologists interacting to exchange ideas, news, technical information, and best practices to solve problems and get the most from Cadence technology. The community is open to everyone, and to provide the most value, we require participants to follow our Community Guidelines that facilitate a quality exchange of ideas and information. By accessing, contributing, using or downloading any materials from the site, you agree to be bound by the full Community Guidelines.