Sensing Power MOSFET Junction Temperature Using Circuit Output Current Ringing Decay

Abstract

Junction temperature (T j ) sensing requirements for fast MOSFET junction temperature control and high-power fast switching power converter protection are not easily met with nonintrusive techniques. This paper presents a noninvasive circuitmodel-based sensing method suitable for a high-bandwidth hard-switching converter power MOSFET junction temperature estimation without any additional temperature detector. For the purpose of demonstrating MOSFET junction temperature sensing, a chopper circuit is used. The ringing superimposed with a circuit load current is used for MOSFET junction temperature estimation. A "gate drive-R DS−on −L−C" resonant model is implemented, indicating the mechanism of power MOSFET turn-on dynamics. Modeling includes the gate-drive output parasitics, power MOSFET intrinsic parameters, PCB parasitics, and load parasitics. To evaluate the methodology, LTspice simulation and experimental results are studied.

Sensing IGBT junction temperature using gate drive output transient properties

“…Simulation and experimental results indicated that the time constant of the load voltage ringing decay (or DC bus current ringing decay) can be used to estimate R DS-on and the corresponding T j . [1] was extended in [10] from the "voltage source-R DS-on -L-C" resonant model to the "gate drive-R DS-on -L-C' resonant model. Both [1] and [10] utilize the MOSFET R DS-on versus T j relationship for indirect T j estimation.…”

“…[1] was extended in [10] from the "voltage source-R DS-on -L-C" resonant model to the "gate drive-R DS-on -L-C' resonant model. Both [1] and [10] utilize the MOSFET R DS-on versus T j relationship for indirect T j estimation. However, using Fourier transforms requires numerical computations that make [1] and [10] impractical for real-time temperature estimation.…”

“…Both [1] and [10] utilize the MOSFET R DS-on versus T j relationship for indirect T j estimation. However, using Fourier transforms requires numerical computations that make [1] and [10] impractical for real-time temperature estimation. The method proposed by [1] is regarded as the first generation indirect T j estimation, as shown in Fig.…”

“…1. The method proposed by [10] is regarded as the second generation indirect T j estimation, as shown in Fig The methods proposed by [1] and [10] utilize the converter output ringing waveform, which can be sensitive to converter load and the switching transient of other semiconductors in the circuit. In contrast, [11] studied the T j dependency of power MOSFET gate drive output waveforms, which was proved insensitive to converter load and the switching transient of other semiconductors in the circuit.…”

Enabling Junction Temperature Estimation via Collector-Side Thermo-Sensitive Electrical Parameters Through Emitter Stray Inductance in High-Power IGBT Modules

“…Since the number of d-TSEPs is larger than that of static TSEPs, more and more d-TSEP methods are being developed for Tj estimation recently [21,[24][25][26]. Practically, according to the magnitude of electrical parameters, TSEPs can be divided further into gate-related TSEPs and collector-related TSEPs, as depicted in Fig.1.…”