The　electrical　method　allows　for　quick,　non-destructive,　and　accurate　thermal　resistance　assessment　in　power　devices.　However,　in　practical　engineering　applications,　the　presence　of　decoupling　capacitors　affects　the　acquisition　of　the　in-situ　thermal　resistance　of　the　devices.　Therefore,　periodic　thermal　resistance　monitoring　requires　repeated　disassembly　of　the　devices,　which　can　introduce　new　reliability　issues.　This　paper　employs　an　operational　circuit　design　to　develop　a　method　for　in-situ　thermal　resistance　measurement.　The　feasibility　of　this　method　is　validated　through　the　analysis　of　static　and　dynamic　characteristics.　©　Published　under　licence　by　IOP　Publishing　Ltd.