Exact switching model
Loop gain from the switching circuit, valid up to and above half the switching frequency.
Loop gain on the real switching model.
Margins from the switching converter itself, not an averaged approximation, with a stability verdict and an auto-tuned compensator.
What does the Loop & Stability Designer do?
The Loop & Stability Designer measures the control-loop gain of a switching power converter on its exact switching model rather than an averaged one, so effects near half the switching frequency are included. It reports gain and phase margin, gives a stability verdict from the Floquet multipliers of the periodic steady state, maps the subharmonic boundary for peak-current-mode control, and auto-tunes a type II or type III compensator. A brute-force frequency-response analysis on the same engine is available as an independent check.
Features
Stability verdict
Floquet multipliers of the steady state say whether the loop is stable, not just the margins.
Peak current mode
Subharmonic oscillation boundary and slope-compensation map.
Auto-tune
Type II and type III compensator values for a target crossover and margin.
Limits
Margins on hardware also depend on parasitics, sensor delay and digital quantisation, which are estimates unless you model them.
Every module ships with reference cases that run in our CI. See validation for how results are checked.
Related modules
Circuits & Power Electronics
Browser circuit simulator for power electronics: DC, AC, transient, Bode and exact switching steady state in one solve. Opens LTspice .asc schematics. Runs on Mac, Linux, Windows and Chromebooks.
Converter Designer
From input and output specs to candidate converter topologies, real parts and an efficiency, volume and cost Pareto front with error bands, each design verified by an exact steady-state simulation.
Conducted-EMI Predictor
Predict the conducted-emission spectrum of a switching converter through a LISN against CISPR 32, CISPR 25 or FCC Part 15.107 limits, with DM/CM split, peak, quasi-peak and average detectors, margin and a first filter.
Try the Loop & Stability Designer.
Frequently asked questions
Why not use an averaged model?
Averaged models lose accuracy approaching half the switching frequency, which is where current-mode instabilities appear. The exact switching model keeps those effects.
Can it tune my compensator?
Yes. It auto-tunes type II and type III compensators for a chosen crossover frequency and phase margin.