Element evaluation device

Patent metadata

Field	Value
Publication number	US-2025253759-A1
Application number	US-202519094993-A
Country	US
Kind code	A1
Filing date	Mar 30, 2025
Priority date	Sep 30, 2022
Publication date	Aug 7, 2025
Grant date	—

Abstract

An element evaluation device includes a target element connected between first and second nodes; a drive switching element connected between the second node and a third node; an inductor connected between the second node and a fourth node applied with a power supply voltage; a switching circuit that allows the drive switching element to perform switching, a voltage generation circuit connected between the first and fourth nodes, and a capacitor connected between the first and third nodes. After the drive switching element is turned off, when a circulation current flows from the fourth node back to the fourth node via the second node, the first node, and the voltage generation circuit, the voltage generation circuit generates a voltage between the first and fourth nodes, with the first node being a high potential side.

First claim

1 . An element evaluation device comprising:
a target element connected between a first node and a second node; a drive switching element connected between the second node and a third node; an inductor connected between the second node and a fourth node applied with a power supply voltage; a switching circuit configured to allow the drive switching element to perform switching; a voltage generation circuit connected between the first node and the fourth node; and a capacitor connected between the first node and the third node, wherein after the drive switching element is switched from ON state to OFF state, when a circulation current flows in a current loop from the fourth node back to the fourth node via the second node, the first node, and the voltage generation circuit, the voltage generation circuit generates a voltage between the first node and the fourth node, with the first node being a high potential side.

2 . The element evaluation device according to claim 1 , wherein the voltage generation circuit includes one or more diodes having a forward direction from the first node to the fourth node.

3 . The element evaluation device according to claim 1 , wherein the voltage generation circuit is a DC voltage source.

4 . The element evaluation device according to claim 1 , wherein the target element is a target transistor or a target diode.

5 . The element evaluation device according to claim 1 , wherein the target element is a target transistor having a drain or a collector connected to the first node, and a source or an emitter connected to the second node.

6 . The element evaluation device according to claim 5 , wherein the target transistor is a MOSFET having a drain connected to the first node and a source connected to the second node, and wherein the MOSFET is formed of silicon carbide.

7 . The element evaluation device according to claim 5 , wherein the target transistor is fixed to OFF state.

8 . The element evaluation device according to claim 1 , wherein the target element is a target diode having a cathode connected to the first node and an anode connected to the second node.

9 . The element evaluation device according to claim 1 , wherein a turn-on delay time of the drive switching element is 5 nanoseconds or less.

10 . The element evaluation device according to claim 1 , wherein
the drive switching element is constituted of a semiconductor component including a semiconductor chip in which a MOSFET is formed, a package housing the semiconductor chip, and a drain terminal, a power source terminal, a driver source terminal, and a gate terminal, which are exposed from the package, a gate electrode of the MOSFET in the semiconductor chip is connected to the gate terminal, a drain electrode of the MOSFET in the semiconductor chip is connected to the second node via the drain terminal, a source electrode of the MOSFET in the semiconductor chip is connected to the third node via the power source terminal including a package inductance component and is connected to the driver source terminal without going through the power source terminal, and the switching circuit supplies a gate signal between the gate terminal and the driver source terminal, so as to allow the drive switching element to perform switching.

11 . The element evaluation device according to claim 1 , wherein the drive switching element is a MOSFET formed of silicon carbide.

12 . The element evaluation device according to claim 1 , wherein the switching circuit allows the drive switching element to perform switching at a frequency of 10 kHz or more.

13 . The element evaluation device according to claim 1 , wherein the switching circuit allows the drive switching element to perform switching at a predetermined frequency, and sets an ON time of the drive switching element to 500 nanoseconds or less in each period of switching of the drive switching element.

14 . The element evaluation device according to claim 1 , wherein the power supply voltage is 600 V or more with respect to the potential at the third node.

Assignees

• Rohm Co Ltd

Inventors

• SENGA Kei
• Kitagawa Seiya

Classifications

• H02M3/155

  using semiconductor devices only · CPC title

• H02M1/088 Primary

  for the simultaneous control of series or parallel connected semiconductor devices · CPC title

• H03K17/102 Primary

  in field-effect transistor switches · CPC title

• G01R31/26

  Testing of individual semiconductor devices (testing of photovoltaic devices H02S50/10; testing or measuring during manufacture or treatment {H10P74/00}) · CPC title