Driving device and driving method for semiconductor element

A driving device for a semiconductor element in which a current flowing from a first main electrode to a second main electrode is controlled in accordance with a voltage of a control electrode, the driving device comprising:

• a driving circuit to output one of a first voltage and a second voltage to the control electrode in accordance with a gate signal that controls ON/OFF of the semiconductor element, the first voltage being a voltage for turning on the semiconductor element, the second voltage being a voltage for turning off the semiconductor element;
• a protection circuit to perform a protection operation of turning off the semiconductor element when an abnormality occurs during an ON period of the semiconductor element;
• and
• a selection circuit to switch a mode of the protection operation performed by the protection circuit, in accordance with a driving state of the semiconductor element responsive to a turn-on command, wherein
• the selection circuit outputs a selection signal to the protection circuit such that the protection circuit performs a first protection operation until a voltage or a current of the control electrode reaches a predetermined reference value in the ON period, and the protection circuit performs a second protection operation after the voltage or the current of the control electrode reaches the reference value,
• in a first time period in which the first protection operation is instructed by the selection signal, the protection circuit controls the driving circuit such that the driving circuit outputs the second voltage to the control electrode in response to detection of the abnormality of the semiconductor element, and
• in a second time period in which the second protection operation is instructed by the selection signal, the protection circuit controls the driving circuit such that a time period in which a third voltage is output to the control electrode is provided and then the driving circuit outputs the second voltage to the control electrode in response to detection of the abnormality of the semiconductor element, and
• the third voltage is a voltage between the first voltage and the second voltage.

A driving method for a semiconductor element in which a current flowing from a first main electrode to a second main electrode is controlled in accordance with a voltage of a control electrode, the driving method comprising:

• outputting a first voltage to the control electrode in accordance with a turn-on command of the semiconductor element, the first voltage being a voltage for turning on the semiconductor element;
• performing a protection operation of turning off the semiconductor element when an abnormality occurs during an ON period of the semiconductor element;
• and
• switching a mode of the protection operation in accordance with a driving state of the semiconductor element responsive to the turn-on command, wherein
• the performing a protection operation includes:
• performing a first protection operation in a first time period of the ON period in which an elapsed time from a timing at which turn-on of the semiconductor element is started in accordance with a gate signal that controls ON/OFF of the semiconductor element is equal to or less than a predetermined first time, the first protection operation being an operation of outputting a second voltage for turning off the semiconductor element to the control electrode in response to detection of the abnormality of the semiconductor element;
• and
• performing a second protection operation in a second time period of the ON period in which the elapsed time exceeds the first time, the second protection operation being an operation of providing a time period in which a third voltage is output to the control electrode and then outputting the second voltage to the control electrode in response to detection of the abnormality of the semiconductor element, and
• the third voltage is a voltage between the first voltage and the second voltage.

A driving method for a semiconductor element in which a current flowing from a first main electrode to a second main electrode is controlled in accordance with a voltage of a control electrode, the driving method comprising:

• outputting a first voltage to the control electrode in accordance with a turn-on command of the semiconductor element, the first voltage being a voltage for turning on the semiconductor element;
• performing a protection operation of turning off the semiconductor element when an abnormality occurs during an ON period of the semiconductor element;
• and
• switching a mode of the protection operation in accordance with a driving state of the semiconductor element responsive to the turn-on command, wherein
• the performing a protection operation includes:
• performing a first protection operation in a first time period of the ON period until a voltage or a current of the control electrode reaches a predetermined reference value, the first protection operation being an operation of outputting a second voltage for turning off the semiconductor element to the control electrode in response to detection of the abnormality of the semiconductor element;
• and
• performing a second protection operation in a second time period of the ON period after the voltage or the current of the control electrode reaches the reference value, the second protection operation being an operation of providing a time period in which a third voltage is output to the control electrode and then outputting the second voltage to the control electrode in response to detection of the abnormality of the semiconductor element, and
• the third voltage is a voltage between the first voltage and the second voltage.