{"sections":[{"heading":"Interpret the reduced model","paragraphs":["Historical support explains that compact models can place inductors according to a fundamental-cycle basis. Their placement need not resemble individual segments of the original layout. A changed drawing or ordering can also lead to a different-looking representation.","Treat an unfamiliar representation as a modelling question to verify, rather than relocating elements solely to make the schematic look symmetric."]},{"heading":"Check coupling and completeness","steps":["Check that the intended ports, junctions and connections are present.","Inspect THRESHOLD_K and the matching manual. Removing small couplings changes retained numerical information; a large threshold can remove important coupling.","Compare the reduced circuit's response in an appropriate testbench, as well as the extraction diagnostics.","If a junction or scaling term is missing, record the exact version and a minimal example. Historical fixes do not establish that a new report has the same cause."]},{"heading":"Limit of a small residual","paragraphs":["A low fitting residual alone does not validate the chosen circuit topology or prove the reduced model behaves correctly in its intended application."]}],"canonical_url":"https://www.sun-magnetics.com/knowledge-base/lvs-compact-topology","url":"/knowledge-base/lvs-compact-topology","known_issues":[],"search_record":{"execution":false,"relatedProducts":[],"version_tags":["LVS 1.1.05 manual"],"text":"A compact model has an unfamiliar inductor topology A reduced circuit can use a different basis from the drawing. Inspect connectivity, coupling thresholds and the validation report before redrawing the model. InductEx-LVS Manual v1.1.05; historical support semantics Troubleshooting Interpret the reduced model Historical support explains that compact models can place inductors according to a fundamental-cycle basis. Their placement need not resemble individual segments of the original layout. A changed drawing or ordering can also lead to a different-looking representation. Treat an unfamiliar representation as a modelling question to verify, rather than relocating elements solely to make the schematic look symmetric.  Check coupling and completeness Check that the intended ports, junctions and connections are present. Inspect THRESHOLD_K and the matching manual. Removing small couplings changes retained numerical information; a large threshold can remove important coupling. Compare the reduced circuit's response in an appropriate testbench, as well as the extraction diagnostics. If a junction or scaling term is missing, record the exact version and a minimal example. Historical fixes do not establish that a new report has the same cause.  Limit of a small residual A low fitting residual alone does not validate the chosen circuit topology or prove the reduced model behaves correctly in its intended application. ","id":"lvs-compact-topology","keywords":"","kind":"Troubleshooting","title":"A compact model has an unfamiliar inductor topology","product":"InductEx-LVS"},"version":"Manual v1.1.05; historical support semantics","id":"lvs-compact-topology","related":["/knowledge-base/inductex-negative-resistance","/knowledge-base/inductex-merged-series-values","/knowledge-base/lvs-first-settings"],"downloads":[],"publication_status":"published","numerical_output":null,"provenance":{"execution_checks":[],"figure_evidence":[],"review_notes":["The owner accepted the modelling explanation on 2 November 2026. Applicable release/platform and unrecorded walkthrough checks remain pending."],"scope":"Recorded inputs/builds only. Complete walkthrough and final-package acceptance remain separate.","verification_requirements":{"gui_method":"not-required-for-this-answer","status":"review-incomplete","illustrations":"not-required-for-this-answer","required":["technical-review","release-applicability","recovery"],"legacy_walkthrough_field":"pending retained; not evidence of a complete scenario"},"sources":[{"id":"published:lvs-manual-1.1.05","section":"Compact-model settings, including THRESHOLD_K"},{"id":"support:SUP-020","section":"Historical fundamental-cycle and omitted-coupling explanations"},{"id":"owner:technical-review-20261102","section":"Owner accepted this modelling explanation; version limits and execution scope retained"}]},"title":"A compact model has an unfamiliar inductor topology","type":"Troubleshooting","markdown_url":"/_functions/kbResource?path=markdown%2Flvs-compact-topology.md","summary":"A reduced circuit can use a different basis from the drawing. Inspect connectivity, coupling thresholds and the validation report before redrawing the model.","product":"InductEx-LVS"}