Noise-Robust Online Measurement of the On-State Resistance of the Power Semiconductor Devices in PWM Converters

The on-state resistance of power semiconductor devices,RDUT, is used to estimate the remaining useful life (RUL) of the devices. Conventional online measurement ofRDUTinvolves on-state voltage measurement of the on-state device, which is easily polluted by switching noise to limit the measurement accuracy. This paper proposes a new noise-robust method to measure the increment ofRDUTby inductor current and input/output DC voltage of DC-DC converters. The proposed method features higher accuracy in predicting RUL than the conventional one because the inductor current is immune to switching noise. Experimental results showed 99.2% maximum accuracy between the actual and measuredRDUTof sample MOSFETs.