Calorimetry-Based PWM Power-Cycling for Loss Separation and Health Monitoring of Half-Bridge Devices

Ensuring reliable health monitoring of semiconductor devices in high-performance power converters requires measurement approaches that remain accurate under fast switching and strong EMI. This presentation introduces a calorimetry-based pulse width modulation power cycling test (PWM-PCT) combined with a new back-to-back energy recycling topology specifically tailored for half-bridge devices. The proposed topology enables symmetric low ripple current excitation and symmetrical loss distribution in upper and lower switches of the half-bridge, key requirements for accurate calorimetric loss assessment. Using PWM-PCT with controlled frequency sweeps, the method enables separation of conduction and switching losses, allowing the dominant aging mechanisms, bond-wire/metallization degradation and gate-oxide stress, to be distinguished without relying on high-bandwidth electrical measurements. The calorimetric approach reduces susceptibility to EMI, eliminates the need for invasive measurement hardware, and offers a simple pathway toward in-situ monitoring of semiconductor health.