Topology Designers

LLC Resonant Converter Designer

Search resonant-tank candidates across input-voltage and load corners, then review frequency range, operating modes, design margin, state-plane trajectories, and time-domain waveforms.

Trajectory-guided ODE State-plane analysis Browser-based

Step 1

Specifications

Set electrical requirements and the candidate search space without changing the default design grid.

Electrical Specifications Input topology Rectifier topology

Vin,min [V] Vin,typ [V] Vin,max [V] Model

Output and Load

Output voltage Vo [V] Rated output current Io [A] Minimum continuous load [%] Overload allowance [%] Rated power [W] Rated load [ohm] Operating points

Frequency Constraints Resonant frequency f0 [kHz]

Minimum fs

30% · 30 kHz

Maximum fs

250% · 250 kHz

Switching-frequency limits are set as a percentage of f0 and displayed in kHz.

Search Constraints

The center transformer ratio is calculated from the typical input voltage and topology.

n-2 n-1 n n+1 n+2

Five transformer-ratio candidates are generated automatically.

9 k = Lm / Lr candidates 13 Qnom candidates

The default search evaluates 5 x 9 x 13 = 585 candidates.

Ready to evaluate 585 candidates across 9 operating points.

Step 2

Search Summary

Candidate counts update after the search completes.

Total585

Feasible—

Marginal—

Failed / Numerical—

Run time—

Step 3

Recommended Designs

Top-ranked candidates by worst-case margin and constraint headroom.

Rank / Status	n	k	Qnom	Lr [µH]	Lm [µH]	Cr [nF]	fs range [kHz]	Ir,pk [A]	Ir,rms [A]	VCr,pk [V]	Worst margin	Limit
Run the design search to view recommended designs.

Step 4

Selected Design

Review the active candidate and its limiting margin.

Run the design search to select a candidate.

Step 5

Transformer-ratio Overview

Compare feasible regions across the five generated ratio candidates.

Run the design search to compare the feasible regions of five transformer-ratio candidates.

Step 6

Candidate Space

Each cell represents one k and Q combination for the active transformer ratio.

Feasible Marginal Failed Numerical issue Limits: F↑ high frequency, F↓ low frequency, I current, V voltage, Z commutation, N numerical.

Step 7

Operating Points

Select any operating point to update the state-plane and time-domain views.

Operating point	Vin [V]	Load	fs [kHz]	fs/f0	Control branch	Ir,pk [A]	Ir,rms [A]	VCr,pk [V]	Commutation current [A]	Free interval	ODE residual	Result
Select a candidate design to inspect operating points.

Step 8

Advanced Analysis

Use the plots to inspect gain envelope, operating mode, state trajectory, and waveforms for the selected design.

Gain Envelope and Required Switching-Frequency Range

The envelope shows the switching-frequency range required to regulate each operating condition.

Target gain range—

Required fs range—

Low-frequency margin—

High-frequency margin—

Tightest corner—

The shaded band spans light load through overload. Target gain lines map the input-voltage range, and markers show the nine solved ODE operating points.

State-plane Trajectory

Select an operating point to show the vCr-iLr state trajectory.

Forward rectifier clamp Free resonance Reverse rectifier clamp Switching transition

Operating-mode Summary

Brief interpretation of the selected corner.

Select a valid operating point to view the mode summary.

Time-domain Waveforms

Select an operating point to show three switching periods of ODE waveforms.

The waveforms use the same solved operating point as the state-plane view. Commutation current is an idealized proxy and does not include Coss, dead time, or parasitics.

Model boundary: ideal switches, ideal rectifier, constant output voltage, continuous frequency modulation, no burst or skip operation, and no parasitic elements.