Switching element control device

Patent metadata

Field	Value
Publication number	US-10833574-B2
Application number	US-201916547627-A
Country	US
Kind code	B2
Filing date	Aug 22, 2019
Priority date	Nov 15, 2018
Publication date	Nov 10, 2020
Grant date	Nov 10, 2020

Abstract

A switching element control device for controlling a switching element incorporating a reverse conducting diode is provided. The switching element control device includes: a voltage detection circuit detecting a voltage across first and second main electrodes of the switching element; a comparator circuit comparing the voltage detected by the voltage detection circuit with a threshold voltage; and a drive circuit controlling driving of the switching element. The comparator circuit controls the drive circuit so that an on signal is not provided to the switching element when the detected voltage exceeds the threshold voltage.

First claim

What is claimed is:

1. A switching element control device for controlling a switching element incorporating a reverse conducting diode, the switching element control device comprising:
a voltage detection circuit detecting a voltage across first and second main electrodes of the switching element;
a comparator circuit comparing the voltage detected by the voltage detection circuit with a threshold voltage; and
a drive circuit controlling driving of the switching element, wherein
the comparator circuit controls the drive circuit so that an on signal is not provided to the switching element when the detected voltage exceeds the threshold voltage, and
the voltage detection circuit inputs the detected voltage into the comparator circuit when a positive bias for the reverse conducting diode is applied across the first and second main electrodes, and does not input the detected voltage into the comparator circuit when a positive bias for the switching element is applied across the first and second main electrodes.

2. The switching element control device according to claim 1 , wherein
the voltage detection circuit includes a pulse transformer having a winding ratio of 1:1, and
a primary winding of the pulse transformer is connected to the first and second main electrodes, and an output of a secondary winding of the pulse transformer is provided to the comparator circuit through a diode connected to block the detected voltage when the positive bias for the switching element is applied.

3. The switching element control device according to claim 1 , wherein
when the detected voltage exceeds the threshold voltage, the comparator circuit inputs, as a low potential signal, an output signal into a logic AND circuit provided to precede the drive circuit, and
when an output signal of the logic AND circuit is the low potential signal, the drive circuit does not operate.

4. The switching element control device according to claim 1 , wherein
the comparator circuit uses the threshold voltage as a built-in potential voltage of a pn junction.

5. A switching element control device controlling a switching element incorporating a reverse conducting diode, the switching element control device comprising:
a voltage detection circuit detecting a voltage across first and second main electrodes of the switching element;
a comparator circuit comparing the voltage detected by the voltage detection circuit with a threshold voltage; and
a drive circuit controlling driving of the switching element, wherein
the comparator circuit controls the drive circuit so that an on signal is not provided to the switching element when the detected voltage exceeds the threshold voltage,
the switching element comprising:
a region of formation of the reverse conducting diode and a region of formation of the switching element alternately arranged in stripes in plan view, and
a stripe width of the region of formation of the reverse conducting diode and a stripe width of the region of formation of the switching element are set so that snapback occurs when a positive bias for the reverse conducting diode is applied across the first and second main electrodes in a state of the on signal being provided to the switching element.

Assignees

• Mitsubishi Electric Corp

Inventors

• Kaneda Mitsuru
• Takahashi Tetsuo
• Soneda Shinya
• Kamibaba Ryu

Classifications

• H10D12/481 Primary

  having gate structures on slanted surfaces, on vertical surfaces, or in grooves, e.g. trench gate IGBTs · CPC title

• H10D8/422

  PN diodes having the PN junctions in mesas · CPC title

• H10D64/117

  Recessed field plates, e.g. trench field plates or buried field plates · CPC title

• H02M1/0051

  Diode reverse recovery losses · CPC title

• H02M1/0054

  Transistor switching losses (periodically suspending operation of switching converter in low power mode H02M1/0035) · CPC title