A power supply switch circuit includes a first transistor that switches supplying of a first power supply voltage to a power supply terminal of a power amplifier, a switch controller that controls the first transistor and to which a second power supply voltage is applied, and a voltage selector that selects a higher voltage among the first power supply voltage and the second power supply voltage. The selected higher voltage is applied to a body terminal of the first transistor or a gate terminal of the first transistor.

Passive Ethernet by-pass switches, methods of using the same, and systems including the passive Ethernet by-pass switches include a first connection configured to be coupled to a first Ethernet port, a second connection configured to be coupled to a second Ethernet port, and switching circuitry including at least one internal switch operable to allow network communication between the first connection, the second connection, and at least one Ethernet controller, the at least one internal switch including a depletion mode transistor operable to bridge the first connection to the second connection to establish communication between the first connection and the second connection.

An output stage of an Ethernet transmitter is provided. The output stage is coupled to a resistor and includes a first output terminal, a second output terminal, a first transistor, and a first transistor group. The resistor is coupled between the first output terminal and the second output terminal. The first transistor has a first source, a first drain, and a first gate, the first source being coupled to a first reference voltage and the first drain being coupled to the second output terminal. The first transistor group is coupled to the first reference voltage and the first output terminal. The first transistor group includes multiple transistors which are connected in parallel, and the magnitude of the current flowing to the first output terminal is related to the number of transistors that are turned on.

An output stage of an Ethernet transmitter is provided. The output stage is coupled to a resistor and includes a first output terminal, a second output terminal, a first transistor, and a first transistor group. The resistor is coupled between the first output terminal and the second output terminal. The first transistor has a first source, a first drain, and a first gate, the first source being coupled to a first reference voltage and the first drain being coupled to the second output terminal. The first transistor group is coupled to the first reference voltage and the first output terminal. The first transistor group includes multiple transistors which are connected in parallel, and the magnitude of the current flowing to the first output terminal is related to the number of transistors that are turned on.

A switching component and switch assembly. The switching component comprises a first control node, a common node, a plurality of intermediate nodes, a second control node, and a capacitive node; a plurality of transistors connected in series between the control node and the common node, one of the plurality of intermediate nodes being defined between each series connected pair of transistors, each transistor of the plurality of transistors having a gate coupled to the second control node; and a plurality of capacitive components, one capacitive component being coupled between each intermediate node and the capacitive node, a voltage at the capacitive node being configured to be varied with a voltage at the second control node such that, at each intermediate node, the capacitive component is configured to accrue an opposite charge to the transistors.

A multiplexer circuit includes first and second fins each extending in an X-axis direction. First, second, third and fourth gates extend in a Y-axis direction perpendicular to the X-axis direction and contact the first and second fins. The first, second, third and fourth gates are configured to receive first, second, third and fourth data signals, respectively. Fifth, sixth, seventh and eighth gates extend in the Y-axis direction and contact the first and second fins, the fifth, sixth, seventh and eighth gates, and are configured to receive the first, second, third and fourth select signals, respectively. An input logic circuit is configured to provide an output at an intermediate node. A ninth gate extends in the Y-axis direction and contacts the first and second fins. An output logic circuit is configured to provide a selected one of the first, second, third and fourth data signals at an output terminal.

A driver circuit includes three sub-circuits. A first sub-circuit is configured to generate a drive current output by the driver circuit through an output node during first and second regions of operation and includes: a diode coupled to the output node and a first transistor, and a second transistor coupled to the first transistor and a current mirror. A second sub-circuit is configured to generate the drive current during the first and second and a third region of operation and includes: a third transistor coupled to the output node; and a fourth transistor. A third sub-circuit is configured to generate the drive current during the third region of operation and includes: a current source coupled to the current mirror and a buffer; and a fifth transistor coupled to the third transistor and the fourth transistor and configured to receive an output of the buffer.

A driver circuit includes three sub-circuits. A first sub-circuit is configured to generate a drive current output by the driver circuit through an output node during first and second regions of operation and includes: a diode coupled to the output node and a first transistor, and a second transistor coupled to the first transistor and a current mirror. A second sub-circuit is configured to generate the drive current during the first and second and a third region of operation and includes: a third transistor coupled to the output node; and a fourth transistor. A third sub-circuit is configured to generate the drive current during the third region of operation and includes: a current source coupled to the current mirror and a buffer; and a fifth transistor coupled to the third transistor and the fourth transistor and configured to receive an output of the buffer.

In some method and apparatus embodiments, an RF circuit comprises a switch transistor having a source, a drain, a gate, and a body. A gate control voltage is applied to the gate of the switch transistor. A body control voltage is applied to the body of the switch transistor. The body control voltage is a positive bias voltage when the switch transistor is in an on state. In some embodiments, an RF circuit comprises a control voltage applied to the gate of the switch transistor through a first resistance and applied to the body of the switch transistor through a second resistance. The first resistance is different from the second resistance.

In some method and apparatus embodiments, an RF circuit comprises a switch transistor having a source, a drain, a gate, and a body. A gate control voltage is applied to the gate of the switch transistor. A body control voltage is applied to the body of the switch transistor. The body control voltage is a positive bias voltage when the switch transistor is in an on state. In some embodiments, an RF circuit comprises a control voltage applied to the gate of the switch transistor through a first resistance and applied to the body of the switch transistor through a second resistance. The first resistance is different from the second resistance.