Denso Corporation

Hironori Akiyama

Tetsuya Dewa

Masahiro Yamamoto

Akimasa Niwa

Noriyuki Fukui

A gate drive device drives a gate of each of two semiconductor switching elements constituting upper and lower arms of a half bridge circuit. The gate drive device detects a peak value of an element voltage that is a voltage of a main terminal of one of the two semiconductor switching elements, as one semiconductor switching element, or a change rate of the element voltage during a change period in which the element voltage changes. The gate drive device determines whether an energization to the one semiconductor switching element during the change period is a forward energization in which a current flows in a forward direction or a reverse energization in which the current flows in a reverse direction.

Gate drive device

A gate drive device drives a gate of a semiconductor switching element constituting an upper or lower arm of a half bridge circuit which supplies an output current, which is alternating current, to a load. The gate drive device detects a peak value of an element voltage which is a voltage of a main terminal of the semiconductor switching element or a change rate of the element voltage when the semiconductor switching element is switching. The gate drive device acquires a maximum value among a plurality of peak values or a plurality of change rates during a predetermined detection period including a period in which the semiconductor switching element performs switching multiple number of times.

A gate drive apparatus includes a driver, a peak voltage detector and a drive capability controller. The driver drives a gate of a first switching element as one of two switching elements respectively in an upper arm and a lower arm of a half-bridge circuit. The peak voltage detector detects a peak voltage at a second switching element in a situation where the first switching element is turned on. The drive capability controller calculates a value of drive capability when the driver turns on the first switching element, in a condition that the peak voltage at the second switching element does not exceed a tolerance value of a voltage at the second switching element according to a specification of the second switching element, and modifies the drive capability when the driver turns on the first switching element, based on a calculated result of the value of the drive capability.

Gate drive apparatus

A semiconductor device includes a plurality of switching elements electrically connected in parallel with each other, a control unit that outputs a control signal for controlling a current supplied to each of the switching elements, and a temperature estimation unit that estimates a temperature difference between the switching elements. When an estimated temperature difference becomes equal to or higher than a predetermined threshold temperature, the control unit shifts an operation mode to a stop mode for stopping driving of a switching element having a temperature higher than the other.

Semiconductor device

A semiconductor device has a drive unit outputting a first drive signal to a first electrode and a second drive signal to a second electrode, an instruction signal generation unit generating an instruction signal as a basis of the drive signals and a control unit outputting a first control signal as a basis of the first drive signal and a second control signal as a basis of the second drive signal, based on the instruction signal to control the drive unit. The control unit synchronizes the first control signal with the instruction signal, delays a turning-on timing of the second control signal by a predetermined time relative to the instruction signal and determines a turning-off timing of the second control signal based on a previous pulse width of the instruction signal.

Semiconductor device having a double-gate switching element

A drive control apparatus for a semiconductor device having a diode and a transistor includes: a current detection device of a current flowing through the diode; and a control device, which applies a gate drive voltage to the semiconductor device when an on-instruction signal is input. The control device compares the current detection signal with a current threshold value during a first period, in which the on-instruction signal is input, after a second period has elapsed from gate drive voltage application time, or gate drive voltage shut-off time. A transient variation is generated on the current detection signal in the second period. The control device shuts off the gate drive voltage when the current detection signal is equal to or larger than the current threshold value. The control device applies the gate drive voltage when the current detection signal is smaller than the current threshold value.

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Kariya, Japan

Hironori Akiyama