Active clamp circuit and semiconductor device

An active clamp circuit that is connected between a control electrode and a main electrode of a main switch and is configured to control a clamp voltage of the main switch, the active clamp circuit comprising:

• a bypass diode that includes an anode electrode and a cathode electrode, wherein the anode electrode is electrically connected with the control electrode of the main switch, and the cathode electrode is electrically connected with the main electrode of the main switch, and
• a clamp voltage decision part where one terminal of the clamp voltage decision part is electrically connected with the cathode electrode of the bypass diode and an other terminal of the clamp voltage decision part is electrically connected with the anode electrode of the bypass diode and the control electrode of the main switch, wherein
• the clamp voltage decision part includes:
• a diode part where a plurality of sets each formed by connecting at least a Zener diode and a diode in series with opposite polarities are connected in series;
• and a temperature characteristic adjustment resistor that is connected with the diode part in series.

A semiconductor device that forms an active clamp circuit that is connected between a control electrode and a main electrode of a main switch and is configured to control a clamp voltage of the main switch, and is formed on a semiconductor base body on which a device region and a withstand voltage separation region that is formed around the device region are defined from each other, wherein

• the semiconductor device includes, in the device region,
• the semiconductor base body,
• a first main electrode that is formed on a surface of the semiconductor base body on a front surface side,
• a gate pad that is formed on the surface of the semiconductor base body on the front surface side, and is spaced apart from the first main electrode, and
• a second main electrode that is formed on a surface of the semiconductor base body on a back surface side,
• the semiconductor device includes an MOS structure that is formed in a region in which the first main electrode is formed, and
• the semiconductor device includes, in the withstand voltage separation region,
• the semiconductor base body,
• the second main electrode that is formed on the surface of the semiconductor base body on the back surface side,
• an insulation film formed on the surface of the semiconductor base body, and
• a clamp voltage decision part disposed on a region of the insulation film that surrounds the device region as viewed in a plan view where one terminal of the clamp voltage decision part is electrically connected with the gate pad and an other terminal of the clamp voltage decision part is connected with the second main electrode, wherein
• the clamp voltage decision part includes:
• a diode part where a plurality of first first-conductive-type region and a plurality of first second-conductive-type region are alternately disposed adjacently to each other;
• and a temperature characteristic adjustment resistor connected with the diode part in series, and
• the temperature characteristic adjustment resistor has a temperature characteristic corresponding to a temperature characteristic of the diode part.

A semiconductor device that forms an active clamp circuit that is connected between a control electrode and a main electrode of a main switch and is configured to control a clamp voltage of the main switch, and is formed on a semiconductor base body on which a device region and a withstand voltage separation region that is formed around the device region are defined from each other, wherein

• the semiconductor device includes, in the device region,
• the semiconductor base body,
• a first main electrode that is formed on a surface of the semiconductor base body on a front surface side,
• a second main electrode that is formed on a surface of the semiconductor base body on a back surface side, and
• a diode structure that is formed in a region in which the first main electrode is formed, and
• the semiconductor device includes, in the withstand voltage separation region,
• the semiconductor base body,
• the second main electrode that is formed on the surface of the base body on the back surface side, and
• an insulation film formed on the surface of the semiconductor base body, and
• a clamp voltage decision part disposed on a region of the insulation film that surrounds the device region as viewed in a plan view where one terminal of the clamp voltage decision part is electrically connected with the first main electrode and an other terminal of the clamp voltage decision part is connected with the second main electrode, wherein
• the clamp voltage decision part includes:
• a diode part where a plurality of first first-conductive-type region and a plurality of first second-conductive-type region are alternately disposed adjacently to each other;
• and a temperature characteristic adjustment resistor connected with the diode part in series, and
• the temperature characteristic adjustment resistor has a temperature characteristic corresponding to a temperature characteristic of the diode part.