Switching transient based junction temperature estimation of SiC MOSFETs with aging compensation

Abstract

An apparatus and method are provided for estimating junction temperature in a metal-oxide-semiconductor field-effect transistor (MOSFET), such as a silicon carbide (SiC) MOSFET, by capturing switching transients in a source path. A measurement circuit detects a voltage across a stray inductive element during a turn-on or turn-off phase and converts the transient into a pulse having a width proportional to a rise time or fall time. A processor determines junction temperature based on the pulse width and stored correlations between transient durations and temperature. An auxiliary switch circuit may temporarily insert a gate resistance to facilitate transient capture. Aging effects are compensated by analyzing temperature-dependent variations in rise and fall times to adjust temperature estimation over the device lifetime. The system can be integrated into gate driver circuitry for real-time monitoring without substantial disruption to normal converter operation.

Dependencies are inferred from the claim text.