Denso Corporation

Takeyasu Komatsu

Tsuneo Maebara

Ryotaro Miura

Junichi Fukuta

Tomotaka Suzuki

Akito Itou

Yoshiyuki Hamanaka

Tomoyuki Muraho

Syun Miyauchi

Hiroyuki Morita

Yuusuke Murata

Yukio Hosono

In a driver, a clamping module executes a clamping task that clamps an on-off control terminal voltage to be equal to or lower than a clamp voltage for a predetermined time during charging of the on-off control terminal of the switching element. The clamp voltage is lower than an upper limit of the voltage at the on-off control terminal of the switching element. A measuring module measures a parameter value correlated with a sense current correlated with a current flowing between input and output terminals of the switching element. A limiting module discharges the on-off control terminal to limit flow of the current between the input and output terminals if the value of the parameter exceeds a threshold. A setting module variably sets a length of the predetermined time as a function of the parameter value during charging of the switching element's on-off control terminal.

Driver for switching element and control system for rotary machine using the same

A drive unit includes a charging unit which charges an opening/closing control terminal of a switching element to switch a drive state. The switching element includes a sensing terminal which outputs a minute current having a correlation with current flowing between input and output terminals of the switching element. The sensing terminal and either of the output terminal or a member having a potential equal to that of the output terminal are connected via a sensing resistor. The drive unit further includes an active gate control unit which changes a charge rate based on comparison of sensing voltage, which is a potential difference across the sensing resistor, or a rate of change of the sensing voltage with a specified value. The specified value is set based on individual-difference information of the switching element which indicates a characteristic, which affects the sensing voltage, when the drive state is switched.

Drive unit for switching element

In a drive unit for a switching element, a drive circuit changes the switching element between an on-state and an off-state, by controlling a potential difference between a reference terminal, which is one of a pair of ends of a current path of the switching element, and an opening-closing control terminal of the switching element. A determination section determines, if an on-operation command or an off-operation command is inputted as an operation signal for the switching element, whether or not the potential difference has reached a specific value toward which the potential difference shifts, in response to one of the operation commands, with respect to a threshold value by which the switching element is turned on. A forcible processing section removes charge for turning on the switching element from the opening-closing control terminal, if the determination section determines that the potential difference has not reached the specific value.

A drive circuit for a switching element includes a constant-current control unit and a restriction unit. The constant-current control unit performs a constant-current control for charging an open/close control terminal of a switching element to be driven which is a voltage-controlled switching element with electric charge for turning on the switching element. The restriction unit restricts, to a reference voltage, a voltage between the open/close control terminal and a first end of a pair of ends of a current flow path of the switching element for a predetermined period following a start of the constant-current control within a charging process period during which the open/close control terminal is charged with the electric charge such that the switching element is turned on.

Drive circuit for switching element

In the invention, a circuit control device controlling a semiconductor switching element having a control terminal and driven by voltage inputted to the control terminal, has an input voltage detector, a desired voltage setting portion and a control input generation portion. The input voltage detector detects inputted voltage to the switching element. The desired voltage setting portion sets a desired value of the voltage to be inputted to the switching element. The control input generation portion is connected to the control terminal of the switching element, the control input generation portion generating control input to the switching element such that the value to be detected by the input voltage detector closes to the set desired value. The desired voltage setting portion sets the desired value of the voltage on the basis of predetermined characteristics information and operating parameters of the switching element. The operating parameters include temperature of the switching element, Vce, Ice etc.

Circuit control device

In a driver, a discharging module discharges, at a discharging rate, the on-off control terminal of a switching element in response to a drive signal being shifted from an on state to an off state. A changing module determines whether a condition including a level of a sense signal being higher than a threshold level during the on state of the drive signal is met, and changes the discharging rate of the on-off control terminal in response to the drive signal being shifted from the off state to the on state upon determination that the condition is met. A loosening module loosens the condition after a lapse of a period since the shift of the drive signal from the off state to the on state in comparison to the condition immediately after the shift of the drive signal from the off state to the on state.

A drive circuit is provided for a target switching element and opens/closes a current path by controlling an absolute value of a potential difference between one end of the current path and an opening/closing control terminal. The drive circuit includes an integrated circuit connected to the control terminal. The integrated circuit includes an absolute value control circuit controlling the absolute value of the potential difference when the switching element is in an off-state, a stabilization circuit stabilizing the potential difference at a value for maintaining the switching element in an off-state when the switching element is in an off-state, a selection circuit selecting one of control of the absolute value of the potential difference by the control circuit and stabilization of the potential difference by the stabilization circuit, and an on-state terminal connected to the control circuit and the control terminal. The on-state terminal is connected to the stabilization circuit.

In a driver apparatus for driving a voltage-controlled switching element, an absolute value of a voltage difference between a voltage at a reference terminal that is one of terminals of a current path of the switching element and a voltage at the switching control terminal of the switching element is clamped at a clamping voltage greater than a threshold voltage. A voltage greater than the threshold voltage applied to the switching control terminal allows the switching element to be turned on. When the current flowing through the switching element becomes equal to or greater than a clamp threshold after the switching element transitions from an off-state to an on-state, a voltage-drop-rate at which the absolute value is decreased to the clamping voltage is decreased.

Driver apparatus for switching elements

A switching element control apparatus capable of controlling a switching element that is driven by controlling a voltage on its control terminal properly in response to characteristic information of the switching element. The apparatus includes a constant current circuit that applies a constant current to the control terminal, a voltage-limiting circuit that limits the voltage on the control terminal so as not to exceed a limiting voltage, and a control circuit that controls the constant current circuit to apply the constant current to the control terminal when having received a drive signal for turning on the switching element, and controls the voltage-limiting circuit to limit the voltage on the control terminal for a voltage-limiting time period. The control circuit includes a memory storing the characteristic information and variably sets at least one of the limiting voltage, the voltage-limiting time period, and the constant current in response to the characteristic information.

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Chiryu, Japan

Takeyasu Komatsu