A semiconductor device that can perform product-sum operation with low power is provided. The semiconductor device includes a switching circuit. The switching circuit includes first to fourth terminals. The switching circuit has a function of selecting one of the third terminal and the fourth terminal as electrical connection destination of the first terminal, and selecting the other of the third terminal and the fourth terminal as electrical connection destination of the second terminal, on the basis of first data. The switching circuit includes a first transistor and a second transistor each having a back gate. The switching circuit has a function of determining a signal-transmission speed between the first terminal and one of the third terminal and the fourth terminal and a signal-transmission speed between the second terminal and the other of the third terminal and the fourth terminal on the basis of potentials of the back gates. The potentials are determined by second data. When signals are input to the first terminal and the second terminal, a time lag between the signals output from the third terminal and the fourth terminal is determined by the first data and the second data.

A control system includes a control unit. When turning a bidirectional switch element ON, the control unit controls the bidirectional switch element to cause a time lag between a first timing and a second timing. The first timing is a timing when a voltage equal to or higher than a threshold voltage is applied to one gate electrode selected from a first gate electrode and a second gate electrode. The one gate electrode is associated with one source electrode selected from a first source electrode and a second source electrode and having a lower potential than the other source electrode. The second timing is a timing when a voltage equal to or higher than a threshold voltage is applied to the other gate electrode associated with the other source electrode having a higher potential than the one source electrode.

A semiconductor device that can perform product-sum operation with low power is provided. The semiconductor device includes a switching circuit. The switching circuit includes first to fourth terminals. The switching circuit has a function of selecting one of the third terminal and the fourth terminal as electrical connection destination of the first terminal, and selecting the other of the third terminal and the fourth terminal as electrical connection destination of the second terminal, on the basis of first data. The switching circuit includes a first transistor and a second transistor each having a back gate. The switching circuit has a function of determining a signal-transmission speed between the first terminal and one of the third terminal and the fourth terminal and a signal-transmission speed between the second terminal and the other of the third terminal and the fourth terminal on the basis of potentials of the back gates. The potentials are determined by second data. When signals are input to the first terminal and the second terminal, a time lag between the signals output from the third terminal and the fourth terminal is determined by the first data and the second data.

Provided are a determination device and a switch system capable of suppressing a power loss of a semiconductor switch. Determination device is used for semiconductor switch. Semiconductor switch includes junction field-effect transistor having gate and source corresponding to gate. Determination device includes resistor and determination circuit. Resistor has a first end and a second end. The first end of resistor is connected to gate. Determination circuit determines that overcurrent is flowing through semiconductor switch when there is a predetermined change in gate-source voltage of junction field-effect transistor in a range smaller than gate drive voltage provided between the second end of resistor and source.

A switch system includes a bidirectional switch, a first gate driver circuit, a second gate driver circuit, a control unit, a first decision unit, and a second decision unit. The bidirectional switch includes a first source, a second source, a first gate, and a second gate. The first decision unit determines, based on a voltage at the first gate and a first threshold voltage, a state of the first gate in a first period in which a signal to turn OFF the first gate is output from the control unit to the first gate driver circuit. The second decision unit determines, based on a voltage at the second gate and a second threshold voltage, a state of the second gate in a second period in which a signal to turn OFF the second gate is output from the control unit to the second gate driver circuit.

A switch is provided having a switch transistor as well as a monitoring component to monitor a control signal applied to the switch transistor. With the monitoring component, in some implementation a monitoring of the control signal independent from a load path may be possible.

Switch devices using switch transistors with dual gates are provided. The dual gates may be controlled independently from each other by first and second gate driver circuits.

In a semiconductor device capable of product-sum operation, variations in transistor characteristics are reduced. The semiconductor device includes a first circuit including a driver unit, a correction unit, and a holding unit, and an inverter circuit. The first circuit has a function of generating an inverted signal of a signal input to an input terminal of the first circuit and outputting the inverted signal to an output terminal of the first circuit. The driver unit includes a p-channel first transistor and an n-channel second transistor having a back gate. The correction unit has a function of correcting the threshold voltage of one or both of the first transistor and the second transistor. The holding unit has a function of holding the potential of the back gate of the second transistor. The output terminal of the first circuit is electrically connected to an input terminal of the inverter circuit. The time from the input of a signal to the input terminal of the first circuit to the output of a signal from an output terminal of the inverter circuit depends on the potential of the back gate of the second transistor.

An analog switch includes a first field effect transistor (FET) which has a first terminal coupled to an input voltage terminal, a second terminal coupled to a common source, and a control terminal coupled to a common gate. The switch includes a second FET which has a first terminal coupled to an output voltage terminal, a second terminal coupled to the common source, and a control terminal coupled to the common gate. The switch includes a switched current source which has an input coupled to a high voltage supply terminal and an output coupled to the common gate. The switch includes a clamp circuit which has a first terminal coupled to the common gate, a second terminal coupled to the common source, and a third terminal coupled to the low voltage supply terminal.

In accordance with an embodiment, a method includes switching on a transistor device by generating a first conducting channel by driving a first gate electrode and, before generating the first conducting channel, generating a second conducting channel by driving a second gate electrode, wherein the second gate electrode is adjacent the first gate electrode in a current flow direction of the transistor device.