Abstract: A rectifier (107) includes a rectifying MOSFET (101) that performs synchronous rectification, a control circuit (106) that inputs a voltage across a pair of a positive-side main terminal TK and a negative-side main terminal TA of the rectifying MOSFET (101) to determine an ON or OFF state of the rectifying MOSFET (101) based on the inputted voltage, and a capacitor (104) that supplies power to the control circuit (106). The control circuit (106) includes a blocking circuit (105) that inputs the voltage across the pair of main terminals of the rectifying MOSFET (101), to block power supply to the control circuit (106) when the inputted voltage across the pair of main terminals is higher than or equal to a first voltage, and to unblock power supply to the control circuit (106) when the inputted voltage across the pair of main terminals is lower than the first voltage.

Abstract: Provided is a semiconductor device including: a first external electrode which includes a circular outer peripheral portion; a MOSFET chip; a control circuit chip which receives voltages of a drain electrode and a source electrode of the MOSFET and supplies a signal to a gate electrode to control the MOSFET on the basis of the voltage; a second external electrode which is disposed on an opposite side of the first external electrode with respect to the MOSFET chip and includes an external terminal on a center axis of the circular outer peripheral portion of the first external electrode; and an isolation substrate which isolates the control circuit chip from the external electrode. The first external electrode, the drain electrode and the source electrode of the MOSFET chip, and the second external electrode are disposed to be overlapped in a direction of the center axis. The drain electrode of the MOSFET chip and the first external electrode are connected.

Abstract: Provided is a semiconductor device including: a first external electrode which includes a circular outer peripheral portion; a MOSFET chip; a control circuit chip which receives voltages of a drain electrode and a source electrode of the MOSFET and supplies a signal to a gate electrode to control the MOSFET on the basis of the voltage; a second external electrode which is disposed on an opposite side of the first external electrode with respect to the MOSFET chip and includes an external terminal on a center axis of the circular outer peripheral portion of the first external electrode; and an isolation substrate which isolates the control circuit chip from the external electrode. The first external electrode, the drain electrode and the source electrode of the MOSFET chip, and the second external electrode are disposed to be overlapped in a direction of the center axis. The drain electrode of the MOSFET chip and the first external electrode are connected.

Abstract: A rectifier 107 includes a rectifying MOSFET 101 that performs synchronous rectification, a control circuit 106 that inputs a voltage across a pair of a positive-side main terminal TK and a negative-side main terminal TA of the rectifying MOSFET 101 to determine an ON or OFF state of the rectifying MOSFET 101 based on the inputted voltage, and a capacitor 104 that supplies power to the control circuit 106. The control circuit 106 includes a blocking circuit 105 that inputs the voltage across the pair of main terminals of the rectifying MOSFET 101, to block power supply to the control circuit 106 when the inputted voltage across the pair of main terminals is higher than or equal to a first voltage, and to unblock power supply to the control circuit 106 when the inputted voltage across the pair of main terminals is lower than the first voltage.

Abstract: In order to provide a highly accurate and reliable temperature sensing circuit and method, a resistor (10a) having a positive temperature coefficient is connected between the gate terminal (4) and the insulated gate electrode (8a) of the voltage drive type semiconductor device (1a), and the temperature is sensed based on a voltage representing a voltage drop across the resistor in a circuit portion between the gate terminal (4) and the other terminal (5).

Abstract: A fraction of current passing through the P-emitter region and N-base region of a thyristor is by-passed to the base-emitter junction of a PNP transistor. The amount of the base current is dependent on the thyristor current. Thus, as the anode current of the thyristor increases, the base current and hence the collector current of the PNP transistor increases. The collector current by-passed to the PNP transistor is fed, via a switch which is closed during the off-time of the thyistor, to the base-collector path of an NPN transistor whose collector and emitter are respectively connected to the gate and cathode of the thyristor. The turn-on voltage across the collector and emitter of the NPN transistor accordingly becomes lower than the gate-cathode voltage of the thyristor. The base-emitter current of the NPN transistor equals the collector current of the PNP transistor, the collector current being a fraction of the anode current by-passed to the PNP transistor.

Abstract: A voltage across a resistor of a small value connected in series with the cathode or anode of a thyristor is used as a signal source for overcurrent detection. When an overcurrent is generated, the voltage across the resistor increases in excess of the built-in voltage between the base and emitter of a transistor, thereby turning on the transistor. A transistor to take out a current from the gate of the thyristor is turned on. Thus, the self-turn off operation of the thyristor is executed.

Abstract: In a bidirectional linear switch in which two MOS transistors are used with their sources mutually connected, the gates and the substrates of the transistors are also respectively mutually connected and a control signal is applied to the gates. A potential of the polarity such that the substrates are reversely biased to the sources is applied between the substrates and the sources. With this constitution, the linearity of the bidirectional switch is improved.