EPE Association: EPE 2020 - LS2b: Power Devices

EPE 2020 - LS2b: Power Devices
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2020 ECCE Europe - Conference > EPE 2020 - Topic 01: Devices, Packaging and System Integration > EPE 2020 - LS2b: Power Devices

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   (ig, vgs) Monitoring for Fast and Robust SiC MOSFET Short-Circuit Protection with High Integration Capability
By Yazan BARAZI [View]
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Abstract: SiC MOSFETs have a low short circuit withstand time. To address this challenge, a soft shut down and two original detection methods are proposed in this paper, easily implemented and based-on (ig, vgs) diagnosis with no direct time dependency. The first one is dedicated for SiC MOSFETs using his gate-leakage thermal runaway current, and the second one is more general and faster using the gate-charge monitoring. Both are experimentally validated and compared in terms of response-time and robustness capability.

   Active clamping method for SiC MOSFET high power modules - Benefits and Limits
By Robert W. MAIER [View]
[Download]

Abstract: For high power applications, the SiC MOSFET switching speed is limited by the inductive overvoltagedue to the high product of stray inductance and switched current [1]. The active clamping method properly designed for high power applications, allows the increase of the du=dt during the turn-off process without exceeding the MOSFET maximum blocking voltage. This paper investigates the active clamping method via scaled single chip measurements. This scheme includes scaling accordingly the commutation circuit stray inductance and the active clamping path, emulating the full module switching behavior with single chip measurements. In comparison to simple gate resistor controlled switching, the active clamping method allows a higher voltage gradient during the switching process while effectively limiting the overvoltage. Results show, that losses could be reduced in the range by 30\% (for high current) and up to 70\% (for low current). However, special focus has to be placed on the thermal design of the active clamping circuit. The temperature dependent breakthrough voltage of the transient voltage suppression diodes has to be considered for the correct implementation of the active clamping circuit.

   Demonstration of the Short Circuit Ruggedness of the 10 kV Silicon Carbide Bipolar Junction Transistor
By Besar ASLLANI [View]
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Abstract: Static, switching and short circuit characterization of a 10 kV-class Silicon Carbide (SiC) Bipolar Junction Transistor (BJT) is reported. The 2.4 mm² SiC BJT show good static and switching behavior. The current gain is low compared to literature, but several issues have been identified and can be improved. For the first time, the Short Circuit ruggedness of a 10 kV SiC-BJT is reported. These tests show outstanding performance with at least 16 µs withstand time. Several samples have been brought to failure and revealed an outstanding 52,1 J/cm2 of short circuit critical energy at 32\% of breakdown voltage. The failure seems to happen on the top face metallization since the devices fails in blocked mode and the base emitter terminals shorted. The SiC BJT handles without failing at least 3 times the critical Short Circuit energy of the commercial SiC MOSFETs. In addition, switching performance is much better than that of Si-IGBTs.

   Operation principle and perspective performances of Metal Oxide Vacuum Field Effect Transistor - MOVFET
By Annunziata SANSEVERINO [View]
[Download]

Abstract: The operation principle of Metal Oxide Vacuum Field Effect Transistor is presented. It is based on the emission of electrons from a cold cathode and exhibits pentode-like characteristics with very low on resistance thanks to the conduction in a vacuum. Simulations are used to study the effects of the technological choices on the device perspective performances which appear to be very promising in power electronics applications.

EPE 2020 - LS2b: Power Devices
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2020 ECCE Europe - Conference > EPE 2020 - Topic 01: Devices, Packaging and System Integration > EPE 2020 - LS2b: Power Devices
	[return to parent folder]

	(ig, vgs) Monitoring for Fast and Robust SiC MOSFET Short-Circuit Protection with High Integration Capability By Yazan BARAZI	[View] [Download]
Abstract: SiC MOSFETs have a low short circuit withstand time. To address this challenge, a soft shut down and two original detection methods are proposed in this paper, easily implemented and based-on (ig, vgs) diagnosis with no direct time dependency. The first one is dedicated for SiC MOSFETs using his gate-leakage thermal runaway current, and the second one is more general and faster using the gate-charge monitoring. Both are experimentally validated and compared in terms of response-time and robustness capability.

	Active clamping method for SiC MOSFET high power modules - Benefits and Limits By Robert W. MAIER	[View] [Download]
Abstract: For high power applications, the SiC MOSFET switching speed is limited by the inductive overvoltagedue to the high product of stray inductance and switched current [1]. The active clamping method properly designed for high power applications, allows the increase of the du=dt during the turn-off process without exceeding the MOSFET maximum blocking voltage. This paper investigates the active clamping method via scaled single chip measurements. This scheme includes scaling accordingly the commutation circuit stray inductance and the active clamping path, emulating the full module switching behavior with single chip measurements. In comparison to simple gate resistor controlled switching, the active clamping method allows a higher voltage gradient during the switching process while effectively limiting the overvoltage. Results show, that losses could be reduced in the range by 30\% (for high current) and up to 70\% (for low current). However, special focus has to be placed on the thermal design of the active clamping circuit. The temperature dependent breakthrough voltage of the transient voltage suppression diodes has to be considered for the correct implementation of the active clamping circuit.

	Demonstration of the Short Circuit Ruggedness of the 10 kV Silicon Carbide Bipolar Junction Transistor By Besar ASLLANI	[View] [Download]
Abstract: Static, switching and short circuit characterization of a 10 kV-class Silicon Carbide (SiC) Bipolar Junction Transistor (BJT) is reported. The 2.4 mm² SiC BJT show good static and switching behavior. The current gain is low compared to literature, but several issues have been identified and can be improved. For the first time, the Short Circuit ruggedness of a 10 kV SiC-BJT is reported. These tests show outstanding performance with at least 16 µs withstand time. Several samples have been brought to failure and revealed an outstanding 52,1 J/cm2 of short circuit critical energy at 32\% of breakdown voltage. The failure seems to happen on the top face metallization since the devices fails in blocked mode and the base emitter terminals shorted. The SiC BJT handles without failing at least 3 times the critical Short Circuit energy of the commercial SiC MOSFETs. In addition, switching performance is much better than that of Si-IGBTs.

	Operation principle and perspective performances of Metal Oxide Vacuum Field Effect Transistor - MOVFET By Annunziata SANSEVERINO	[View] [Download]
Abstract: The operation principle of Metal Oxide Vacuum Field Effect Transistor is presented. It is based on the emission of electrons from a cold cathode and exhibits pentode-like characteristics with very low on resistance thanks to the conduction in a vacuum. Simulations are used to study the effects of the technological choices on the device perspective performances which appear to be very promising in power electronics applications.