Abstract: A gate drive device drives a gate of a semiconductor switching element and controls a transient voltage corresponding to a voltage of a main terminal of the semiconductor switching element to a target value of the transient voltage at a time of switching the semiconductor switching element. The gate drive device includes a calculation circuit, a drive circuit, a detection circuit, and a learning circuit. The calculation circuit executes a predetermined calculation mode to calculate an operation amount for operating gate drive speed of the semiconductor switching element. The drive circuit drives the gate of the semiconductor switching element according to the operation amount. The detection circuit detects the transient voltage. The learning circuit executes learning processing to change the predetermined calculation mode based on the operation amount calculated by the calculation circuit and the transient voltage detected by the detection circuit.

Abstract: A drive circuit drives a switch configuring a power converter. The drive circuit divides an inter-terminal voltage of a switch. The drive circuit includes a differential circuit having first and second input terminals to which the divided inter-terminal voltages are inputted. The differential circuit outputs an analog voltage based on a voltage difference between the input terminals. The differential circuit executes reset of the output voltage, and with the voltage difference when reset is canceled after reset is executed as a reference voltage, outputs an analog voltage in which an amount of change from the reference voltage is multiplied by an amplification factor. The drive circuit outputs a binary signal based on comparison results between a threshold and the analog voltage outputted from the differential circuit, and sets a transfer rate of a gate charge of the switch when a driving state is switched, based on the output signal thereof.

Abstract: A power converter includes multiple arms, a temperature detector, a voltage detector, a current detector, a heat generation controller, and a heat resistance estimator. Each of the multiple arms includes a target element being a semiconductor element. The heat resistance estimator determines a heat resistance of the target element based on a temperature difference between a first temperature of the target element and a second temperature of the target element, a current through the target element detected by the current detector, and a voltage across conduction terminals of the target element detected by the voltage detector. The first temperature is a temperature detected by the temperature detector in a state where the heat generation controller has not caused the target element to generate heat. The second temperature is a temperature detected by the temperature detector in a state where the heat generation controller has caused the target element to generate heat.

Abstract: In a drive circuit, a differential circuit unit is configured such that resetting of an output voltage of the differential circuit unit is carried out, and the resetting of the output voltage of the differential circuit unit is cancelled. A value of the difference between first and second divided terminal voltages at a timing of cancelling the resetting is defined as a reference voltage. The differential circuit unit generates, as the output voltage, a product of a voltage change from a reference voltage and a predetermined amplification factor after cancelling of the resetting of the differential circuit unit. A signal generator generates a gate signal for the upper- and lower-arm switches in accordance with a value of the output voltage of the differential circuit unit while the upper- and lower-arm switches are in an off state.

Abstract: A gate drive device drives a gate of a semiconductor switching element and controls a transient voltage corresponding to a voltage of a main terminal of the semiconductor switching element to a target value of the transient voltage at a time of switching the semiconductor switching element. The gate drive device includes a calculation circuit, a drive circuit, a detection circuit, and a learning circuit. The calculation circuit executes a predetermined calculation mode to calculate an operation amount for operating gate drive speed of the semiconductor switching element. The drive circuit drives the gate of the semiconductor switching element according to the operation amount. The detection circuit detects the transient voltage. The learning circuit executes learning processing to change the predetermined calculation mode based on the operation amount calculated by the calculation circuit and the transient voltage detected by the detection circuit.

Abstract: A signal detection circuit includes: a voltage dividing circuit having at least a first pair of voltage dividing capacitors connected in series for dividing an input voltage and configured to output a divided voltage, and a detection circuit configured to detect the divided voltage. The first pair of voltage dividing capacitors are included in one semiconductor device. The semiconductor device includes: (i) a semiconductor substrate, (ii) a first conductor layer, (iii) a first dielectric layer, (iv) a second conductor layer, (v) a second dielectric layer, (vi) a third conductor layer, and (vii) a short-circuit portion configured to short-circuit the first conductor layer and the semiconductor substrate.

Abstract: A circuit for detecting a leakage current in a semiconductor element includes a setting circuit and a detector. The semiconductor element includes a first terminal at a high-potential-side of the semiconductor element, a second terminal at a low-potential-side of the semiconductor element, and a control terminal. The control terminal receives a signal for controlling a conduction state between the first terminal and the second terminal. The setting circuit sets a duration during which a charging current flows to the control terminal as an undetectable duration, in response to turning on the semiconductor element. The detector outputs a detected signal based on a condition that the leakage current flowing from the control terminal to the second terminal, after the undetectable duration has been elapsed.

Abstract: A gate drive circuit includes a driver for driving a gate of a switching element, a peak voltage detector, and a drive capacity calculator. The peak voltage detector detects a peak voltage at a main terminal of the switching element when the switching element is OFF. The drive capacity calculator calculates a voltage difference value between the detected peak voltage and an allowable voltage value at the main terminal of the switching element, where the allowable voltage is based on the specifications of the switching element. The drive capacity calculator changes a drive capacity of the driver to gradually decrease the difference between the detected peak voltage and the allowable voltage.

Abstract: A drive circuit drives a switch configuring a power converter. The drive circuit divides an inter-terminal voltage of a switch. The drive circuit includes a differential circuit having first and second input terminals to which the divided inter-terminal voltages are inputted. The differential circuit outputs an analog voltage based on a voltage difference between the input terminals. The differential circuit executes reset of the output voltage, and with the voltage difference when reset is canceled after reset is executed as a reference voltage, outputs an analog voltage in which an amount of change from the reference voltage is multiplied by an amplification factor. The drive circuit outputs a binary signal based on comparison results between a threshold and the analog voltage outputted from the differential circuit, and sets a transfer rate of a gate charge of the switch when a driving state is switched, based on the output signal thereof.

Abstract: In a drive circuit, a differential circuit unit is configured such that resetting of an output voltage of the differential circuit unit is carried out, and the resetting of the output voltage of the differential circuit unit is cancelled. A value of the difference between first and second divided terminal voltages at a timing of cancelling the resetting is defined as a reference voltage. The differential circuit unit generates, as the output voltage, a product of a voltage change from a reference voltage and a predetermined amplification factor after cancelling of the resetting of the differential circuit unit. A signal generator generates a gate signal for the upper- and lower-arm switches in accordance with a value of the output voltage of the differential circuit unit while the upper- and lower-arm switches are in an off state.

Abstract: 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.

Abstract: 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.

Abstract: A gate drive circuit includes a driver for driving a gate of a switching element, a peak voltage detector, and a drive capacity calculator. The peak voltage detector detects a peak voltage at a main terminal of the switching element when the switching element is OFF. The drive capacity calculator calculates a voltage difference value between the detected peak voltage and an allowable voltage value at the main terminal of the switching element, where the allowable voltage is based on the specifications of the switching element. The drive capacity calculator changes a drive capacity of the driver to gradually decrease the difference between the detected peak voltage and the allowable voltage.

Abstract: A gate drive circuit includes a driver for driving a gate of a switching element, a peak voltage detector, and a drive capacity calculator. The peak voltage detector detects a peak voltage at a main terminal of the switching element when the switching element is OFF. The drive capacity calculator calculates a voltage difference value between the detected peak voltage and an allowable voltage value at the main terminal of the switching element, where the allowable voltage is based on the specifications of the switching element. The drive capacity calculator changes a drive capacity of the driver to gradually decrease the difference between the detected peak voltage and the allowable voltage.

Abstract: A transistor drive circuit drives a bipolar-type transistor and a MOSFET that are connected in parallel to each other. A temperature detection element that detects a temperature of a the bipolar-type transistor or the MOSFET. When the temperature is equal to or less than a threshold, the transistor drive circuit turns on both of the MOSFET and the bipolar-type transistor. When the temperature exceeds the threshold, the transistor drive circuit turns on only the bipolar-type transistor.

Abstract: A gate drive circuit includes a driver for driving a gate of a switching element, a peak voltage detector, and a drive capacity calculator. The peak voltage detector detects a peak voltage at a main terminal of the switching element when the switching element is OFF. The drive capacity calculator calculates a voltage difference value between the detected peak voltage and an allowable voltage value at the main terminal of the switching element, where the allowable voltage is based on the specifications of the switching element. The drive capacity calculator changes a drive capacity of the driver to gradually decrease the difference between the detected peak voltage and the allowable voltage.

Abstract: A transistor drive circuit drives a bipolar-type transistor and a MOSFET that are connected in parallel to each other. A temperature detection element that detects a temperature of a the bipolar-type transistor or the MOSFET. When the temperature is equal to or less than a threshold, the transistor drive circuit turns on both of the MOSFET and the bipolar-type transistor. When the temperature exceeds the threshold, the transistor drive circuit turns on only the bipolar-type transistor.

Abstract: A signal processing apparatus for processing a periodic signal outputted from a signal source has a central processing unit and a task switch timer. The central processing unit performs multiple tasks including a signal processing task in parallel. In the signal processing task, the central processing unit starts to process the periodic signal after performing a synchronization processing to synchronize with the periodic signal, setting the task switch timer to a predetermined time upon completion of the synchronization processing, and enabling an interrupt to the central processing unit upon completion of the synchronization processing. The task switch timer disables the interrupt to the central processing unit immediately before expiring. The task switch timer outputs a task switch signal to the central processing unit when expiring, so that the central processing unit switches to the signal processing task.

Abstract: A microprocessor which is adapted to start a second task at a predetermined time when a first task is running if a current time becomes to be equal to the predetermined time is disclosed. The microprocessor executing an instruction read out from a program address updated every time when each execution of instruction is completed, includes update ceasing means for ceasing the program address from being updated when an stopping time comes in order to abort a first task defined by a first computer program and overwriting means for overwriting the program address with an initial address of a second computer program when a predetermined time comes in order to start to execute a second task defined by the second computer program at the predetermined time.

Abstract: It is determined that a write access is executed to a stack area of a main memory. It is then determined whether another write access to a corresponding access destination address in the stack area occurred in the past by referring to an access flag table. In contrast, it is determined that a write access is executed to a global area of the main memory. It is then determined whether another write access to a corresponding access destination address in the global area occurred in the past with referring to an access list. Such a configuration can efficiently provide individual advantages of the determination methods using both the access flag table and the address list. The presence or absence of the past saving execution can be efficiently determined at the time of write access.