A single-pole double-throw switch includes switching units which are set between a first port and a second port and between the first port and a third port, respectively, and are configured to perform complementarily. The each switching unit includes an antenna port, a circuit port, a transmission line configured to couple them, and a switching element connected between the transmission line and a ground. The switching element includes a parallel circuit including a transistor and an inductor connected in parallel, and a capacitor connected in series with the parallel circuit. The transmission line has a characteristic impedance different from a impedance seen inside the switching unit from the antenna port and a impedance seen inside the switching unit from the circuit port.

Apparatus and methods for providing hot-switching immunity for radio frequency switching circuits are disclosed. A radio frequency switching circuit may include both a mechanical switch and a solid-state switch. The mechanical switch may be configurable to couple an output path of a power amplifier to a subsequent component in its transmission path when in a first mechanical switch state and to decouple the output path of the power amplifier from the subsequent component when in a second mechanical switch state. The solid-state switch may be configurable to operatively decouple the mechanical switch from a radio frequency power source when in a first solid-state switch state but not when in a second solid-state switch state. The solid-state switch may be in the first solid-state switch state during transitions of the mechanical switch between the first and second mechanical switch states.

A switch assembly includes a PIN diode connected between an antenna port and a receive port, a first shunt FET device connected between the receive port and ground, a first series FET device connected between the antenna port and a transmit port, a second shunt FET device connected between the transmit port and ground, and a plurality of bias control contacts configured to receive a corresponding plurality of bias control voltages to forward bias the first shunt FET device and the first series FET device into an ON state and to reverse bias the PIN diode and the second shunt FET device into an OFF state in a transmit mode, and to reverse bias the first shunt FET device and the first series FET device into the OFF state and to forward bias the PIN diode and the second shunt FET device into the ON state in a receive mode.

A solid-state relay circuit includes an isolator circuit, a first output terminal, a second output terminal, and an output switch. The output switch is coupled to the isolator circuit, and includes a first transistor, a second transistor, and a diode. The first transistor is coupled to the first output terminal. The second transistor is coupled to the first transistor and the second output terminal. The diode is coupled to the first transistor, the second transistor, and ground, and is configured to block current flow from ground to the first transistor and the second transistor. The isolator circuit is coupled to the output switch and is configured to activate the first transistor and the second transistor.

A solid-state relay circuit includes an isolator circuit, a first output terminal, a second output terminal, and an output switch. The output switch is coupled to the isolator circuit, and includes a first transistor, a second transistor, and a diode. The first transistor is coupled to the first output terminal. The second transistor is coupled to the first transistor and the second output terminal. The diode is coupled to the first transistor, the second transistor, and ground, and is configured to block current flow from ground to the first transistor and the second transistor. The isolator circuit is coupled to the output switch and is configured to activate the first transistor and the second transistor.

An overvoltage protection circuit which can be applied to a motor controller is provided. The overvoltage protection circuit is coupled to an input terminal for receiving an input voltage. The overvoltage protection circuit comprises a switch circuit, a controller, and a comparing unit. When the input voltage is greater than a first voltage, a discharging mechanism is forced to start so as to suppress a voltage spike. When the input voltage is less than a second voltage, the discharging mechanism is closed so as to operate normally.

An overvoltage protection circuit which can be applied to a motor controller is provided. The overvoltage protection circuit is coupled to an input terminal for receiving an input voltage. The overvoltage protection circuit comprises a switch circuit, a controller, and a comparing unit. When the input voltage is greater than a first voltage, a discharging mechanism is forced to start so as to suppress a voltage spike. When the input voltage is less than a second voltage, the discharging mechanism is closed so as to operate normally.

Systems, methods, techniques and apparatuses of power switches are disclosed. One exemplary embodiment is a power switch comprising a first semiconductor device and a second semiconductor device coupled together in a first anti-series configuration between a first terminal and a second terminal; a third semiconductor device and a fourth semiconductor device coupled together in a second anti-series configuration between the first terminal and the second terminal; a controller configured to operate the power switch to simultaneously conduct a first portion of a load current from the first terminal to the second terminal by closing the first semiconductor device and the second semiconductor device, and to conduct a second portion of the load current from the first terminal to the second terminal by closing the third semiconductor device and the fourth semiconductor device.

Systems, methods, techniques and apparatuses of power switches are disclosed. One exemplary embodiment is a power switch comprising a first semiconductor device and a second semiconductor device coupled together in a first anti-series configuration between a first terminal and a second terminal; a third semiconductor device and a fourth semiconductor device coupled together in a second anti-series configuration between the first terminal and the second terminal; a controller configured to operate the power switch to simultaneously conduct a first portion of a load current from the first terminal to the second terminal by closing the first semiconductor device and the second semiconductor device, and to conduct a second portion of the load current from the first terminal to the second terminal by closing the third semiconductor device and the fourth semiconductor device.

A high throw-count multiple-pole FET-based RF switch architecture that provides good RF performance in terms of insertion loss, return loss, isolation, linearity, and power handling. A common port RFC is coupled along a common path to multiple ports RFn. Embodiments introduce additional common RF path branch isolation switches which are controlled by state dependent logic. The branch isolation switches help to isolate the unused branch ports RFn and the unused portion of the common path from the active portion of the common path, and thereby reduce the reactive load attributable to such branches that degrades RF performance of the ports RFn “closer” to the common port RFC. The branch isolation switches can also be used to reconfigure the switch architecture for a multiplex function as well as separate switch path banks for re-configurability of purpose, tuning, or varying switch throw counts and packaging options.