Denso Corporation

Yasutaka Senda

Kazuki Yamauchi

Yusuke Shindo

Ryotaro Miura

Junichi Fukuta

Hiroya Tsuji

Tomotaka Suzuki

Ken Toshiyuki

Koichi Nishibata

Shinichiro Nakata

Teppei Kawamoto

A gate drive circuit includes one output element, a constant current drive circuit, and a constant voltage drive circuit. The output element outputs a gate drive signal to a gate of a gate driven switching element. The constant current drive circuit causes the output element to output the gate drive signal with a constant current. The constant voltage drive circuit causes the output element to output the gate drive signal with a constant voltage.

Gate drive circuit

A drive circuit drives switches that are connected to each other in parallel. The drive circuit includes individual discharge paths, a common discharge path, blocking units, a discharge switch, off-holding switches, and a drive control unit. The drive control unit selects, as target switches to be driven to be turned on, at least two switches among the switches. The at least two switches include a first switch and a second switch. The first switch is last to be switched to an off-state among the at least two switches that are selected as the target switches and switched to an on-state. The second switch is other than the first switch among the at least two switches. The off-holding switches includes a first off-holding switch and a second off-holding switch. After switching the second off-holding switch to an on-state, the drive control unit switches the discharge switch to an on-state.

Drive circuit for switch

In a driving device for driving a plurality of semiconductor switches connected in parallel to each other, a charge side conduction element is disposed in a charge side loop path including a conduction control terminal and a low-potential side conduction terminal of one of the semiconductor switches, and enables a charging current to flow in a conductive state. A discharge side conduction element is disposed in a discharge side loop path including the conduction control terminal and the low-potential side conduction terminal, and enables a discharging current to flow in a conductive state. A voltage detection unit is connected to a current output terminal of at least one of the charge side conduction element and the discharge side conduction element. A resistive element is connected in parallel to at least one of the charge side conduction element and the discharge side conduction element.

Driving device of semiconductor switch

A gate drive device for driving a plurality of semiconductor devices connected in parallel to each other includes a constant current circuit, a plurality of switching element, and a drive controller. The constant current circuit supplies a constant current to respective gates of the plurality of semiconductor devices. The plurality of switching elements is respectively provided on a plurality of paths that connects the constant current circuit and the respective gates of the plurality of semiconductor devices. The drive controller controls driving of the plurality of switching elements to supply the constant current from the constant current circuit to the respective gates of the plurality of semiconductor devices.

Gate drive device

A load driving device includes: a first turn-on drive circuit turning on a first power device as one of a plurality of gate-driven power devices; a second turn-on drive circuit turning on a second power device as another one of the plurality of gate-driven power devices different from the first power device; a current detection circuit detecting a current in at least the first power device; and a control circuit controlling the first turn-on drive circuit to turn on the first power device by applying a gate voltage with a first change rate, and subsequently controlling the second turn-on drive circuit to turn on the second power device by applying a gate voltage with a second change rate, which is larger than the first change rate, based on a condition in which the current detection circuit does not detect an overcurrent in the first power device.

Load driving device

In an integrated circuit formed into a single chip, a drive signal generating unit generates drive signals for switching elements of a power conversion circuit. A monitoring unit monitors a microcomputer that calculates generation information that is information used to generate the drive signals, and determines whether or not an abnormality has occurred in the microcomputer. An angle converting unit converts an output signal of an angle sensor to rotation angle information of a rotating electric machine. A drive signal generating unit generates the drive signals for controlling driving of the rotating electric machine based on the generation information and the rotation angle information when the monitoring unit determines that an abnormality has not occurred in the microcomputer, and generates the drive signals based on the rotation angle information, without using the generation information, when the monitoring unit determines that an abnormality has occurred in the microcomputer.

Integrated circuit

In a gate driver for driving a first transistor with a constant current, a constant current circuit supplies the constant current to a gate of the first transistor. A second transistor has a gate supplied with a gate reference voltage as a reference for a drive voltage to turn ON the first transistor and is connected in a forward direction in a path from the constant current circuit to the gate of the first transistor. A controller drives the first transistor by operating the constant current circuit when an ON instruction is inputted. The controller sets the gate reference voltage to a first value when the ON instruction is inputted and then changes the gate reference voltage to a second value greater than the first value when a predetermined timing comes under a condition where the first transistor is not in an overcurrent state.

Gate driver

In a gate drive circuit, a gate voltage limiting circuit limits a gate voltage equal to or lower than a first limiting voltage in a first period, and limits the gate voltage equal to or lower than a second limiting voltage in a second period. A gate voltage generation circuit generates a drive voltage having a first set value, which is determined to operate the transistor in an active region, in the first period, and generates the drive voltage having a second set value, which is determined based on a gate withstand voltage of the transistor and loss in an on operation of the transistor in a saturated region, in the second period. The first limiting voltage is higher than the first set value by a predetermined value. The second limiting voltage is higher than the second set value by a predetermined value.

Gate drive circuit for transistor

A load driver includes a switching element connected to a load, a constant current generator that generates a constant current, and a driver circuit that turns on the switching element for an on-period, which depends on a value of the constant current and is shortened with an increase in the value of the constant current. The constant current generator supplies a first constant current having a first current value to the driver circuit during the on-period, and supplies a second constant current having a second current value smaller than the first current value after the on-period has elapsed and the switching element reaches an on state.

Load driver with constant current variable structure

A gate drive circuit includes a power supply circuit that has an output switch function for switching a voltage value of a drive voltage between two levels, a gate-ON drive circuit that outputs a constant electric current toward a gate of an IGBT from an output terminal of the power supply circuit, and a control section performs a constant electric current drive of a gate of the IGBT at a time of a turn-ON by operating the gate-ON drive circuit. At a turn-ON start time, the control section sets the drive voltage to a relatively-high first set value, and then switches the drive voltage to a relatively-low second set value at a switch timing after a mirror period end time.

A PWM duty cycle converter includes a PWM signal generator, a timing signal generator, a limit signal generator, and a duty cycle limiter. The PWM signal generator generates a first PWM signal by comparing a triangular carrier wave with a duty command from a signal source. The timing signal generator generates a timing signal synchronously with at least one of a maximum value and a minimum value of the amplitude of the carrier wave. The limit signal generator generates a limit signal in response to the timing signal. The limit signal sets at least one of an upper limit and a lower limit on a duty cycle of the first PWM signal. The duty cycle limiter combines the first PWM signal and the limit signal to output a second PWM signal having a limited duty cycle.

PWM duty cycle converter

A load driving apparatus for driving a load with a constant current includes a shunt resistor and a driver circuit. A shunt current corresponding to the constant current flows though the shunt resistor. The driver circuit is connected to a first end of the shunt resistor to supply the constant current corresponding to the shunt current to the load. The driver circuit includes a reference voltage source for generating a predetermined reference voltage. The driver circuit adjusts the magnitude of the constant current by performing a feedback-control of the magnitude of the shunt current in such a manner that a first voltage corresponding to the reference voltage and a second voltage corresponding to a voltage at the first end of the shunt resistor become equal to each other.

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Kariya, Japan

Yasutaka Senda