Abstract: A switching circuit includes a wiring into which a parallel circuit of a first IGBT and a second IGBT is inserted, and a gate control circuit. The gate control circuit has a first switching element configured to control a gate potential of the first IGBT according to a potential of a second principal electrode, and a second switching element configured to control a gate potential of the second IGBT according to a potential of a fourth principal electrode. An output terminal of the control device is connected to the first switching element through a first switch and is connected to the second switching element through a second switch. The control device applies a control signal to the output terminal in a state where the first switch and the second switch are turned on when switching both of the first IGBT and the second IGBT.

Abstract: A switching circuit switches a first IGBT and a second IGBT. A control circuit is equipped with a first switching element that is configured to be able to control a gate current of the first IGBT, a second switching element that is configured to be able to control a gate current of the second IGBT, and a third switching element that is connected between an electrode of the first IGBT and an electrode of the second IGBT. The control circuit controls a turn on timing and turn off timing.

Abstract: A switching circuit switches a first IGBT and a second IGBT. A control circuit is equipped with a first switching element that is configured to be able to control a gate current of the first IGBT, a second switching element that is configured to be able to control a gate current of the second IGBT, and a third switching element that is connected between an electrode of the first IGBT and an electrode of the second IGBT. The control circuit controls a turn on timing and turn off timing.

Abstract: A switching circuit includes a wiring into which a parallel circuit of a first IGBT and a second IGBT is inserted, and a gate control circuit. The gate control circuit has a first switching element configured to control a gate potential of the first IGBT according to a potential of a second principal electrode, and a second switching element configured to control a gate potential of the second IGBT according to a potential of a fourth principal electrode. An output terminal of the control device is connected to the first switching element through a first switch and is connected to the second switching element through a second switch. The control device applies a control signal to the output terminal in a state where the first switch and the second switch are turned on when switching both of the first IGBT and the second IGBT.

Abstract: The invention provides a signal transmission device that transmits a signal applied to a pair of input terminals to a pair of output terminals insulated electrically from the pair of input terminals while reducing the influence of an external noise magnetic field. The signal transmission device has a pair of coils, a pair of magnetic sensors and a signal output section. Each of the coils is connected between the pair of input terminals. Each of the coils generates a magnetic field respectively in response to the input signal applied between the pair of input terminals. A direction of the magnetic field generated by one of the coils is opposite to a direction of the magnetic field generated by the other of the coils. Each of the magnetic sensors corresponds to one of the coils exclusively. Each of the magnetic sensors detects the magnetic field generated by the corresponding coil, and outputs a detection signal in response to the detected magnetic field.

Abstract: The invention provides a signal transmission device that transmits a signal applied to a pair of input terminals to a pair of output terminals insulated electrically from the pair of input terminals while reducing the influence of an external noise magnetic field. The signal transmission device has a pair of coils, a pair of magnetic sensors and a signal output section. Each of the coils is connected between the pair of input terminals. Each of the coils generates a magnetic field respectively in response to the input signal applied between the pair of input terminals. A direction of the magnetic field generated by one of the coils is opposite to a direction of the magnetic field generated by the other of the coils. Each of the magnetic sensors corresponds to one of the coils exclusively. Each of the magnetic sensors detects the magnetic field generated by the corresponding coil, and outputs a detection signal in response to the detected magnetic field.

Abstract: A voltage controlled oscillator includes an oscillator having at least one first capacitor. The oscillator receives first and second input voltages and charges the first capacitor with a first current corresponding to the first input voltage. The oscillator oscillates at a frequency corresponding to the first and second input voltages. To remove the adverse influence on the oscillating frequency by the change of process parameters caused in the stage of manufacturing the voltage controlled oscillators, a second capacitor is charged for a predetermined period by a current corresponding to the first voltage. After the charging of the second capacitor ends, a sample/hold circuit samples and holds the charged voltage across the second capacitor. An operational amplifier receives, at its positive input terminal, the output voltage of the sample/hold circuit, and, at its negative input terminal, the reference voltage.

Abstract: An input MOS transistor receives an input voltage and produces a current corresponding to the input voltage. A charge/discharge circuit charges a capacitor alternately in two different directions by the output current of the transistor. A select circuit alternately selects and produces one of the potentials at either of the electrodes of the capacitor. A single two-input comparator compares a reference potential with a potential of the output signal of the select circuit. The select circuit produces a signal corresponding to the comparison result. The select circuit allows the output signal of the comparator to be transmitted alternately to the set input terminal and the reset input terminal of a flip-flop. The flip-flop is set and reset by the output signal of the switch means to produce an oscillating signal. According to a change in the level of the oscillating signal, the charge/discharge circuit switches the charging direction of the capacitor.

Abstract: Disclosed is a switched capacitor filter circuit employing the equivalent resistance of a switched capacitor circuit as the resistive element in a frequency dependent impedance converting circuit.

Abstract: A signal corresponding to an analog input signal is supplied to one of two input terminals of a two-input, one-output MOS differential amplifier. A reference voltage signal is supplied to the other of the two input terminals of the MOS differential amplifier. A bipolar transistor having one end connected to an analog signal output terminal is driven by a signal from the output terminal of the MOS differential amplifier. A loudspeaker is driven by the bipolar transistor.

Abstract: An operational amplifier having a differential amplifier section, a level shifting section, an output section and a bias section. In the operational amplifier, the bias section senses any changes in the power voltage and controls the level shifting of the level shifting section with the sensed change in the power voltage so as to remove an offset component in the output voltage of the differential amplifier section which arises from the power voltage change.

Abstract: A MOS power amplifier circuit comprised of a load driver including two p-channel MOSFETs connected in series, a preamplifier for amplifying an analog input signal and supplying the amplified one to the gate of one of the MOSFETs and for rendering the impedance of the two MOSFETs low; and an inverting amplifier for invert-amplifying the output signal from the preamplifier and supplying the amplified one to the gate of the other MOSFET. The operating voltage of the preamplifier and the inverting amplifier is higher than that of the load driver.