A signal detection circuit includes: a voltage dividing circuit having at least a first pair of voltage dividing capacitors connected in series for dividing an input voltage and configured to output a divided voltage, and a detection circuit configured to detect the divided voltage. The first pair of voltage dividing capacitors are included in one semiconductor device. The semiconductor device includes: (i) a semiconductor substrate, (ii) a first conductor layer, (iii) a first dielectric layer, (iv) a second conductor layer, (v) a second dielectric layer, (vi) a third conductor layer, and (vii) a short-circuit portion configured to short-circuit the first conductor layer and the semiconductor substrate.

A switch circuit of an embodiment includes a high frequency switch, a first charge pump circuit, a boost signal generation circuit, and a second charge pump circuit. The high frequency switch switches transmission and reception of a high frequency signal. The first charge pump circuit generates a first voltage and a second voltage biased to the high frequency switch. When an edge of an input signal is detected, the boost signal generation circuit generates a first boost signal for temporarily increasing drive capacity of the first charge pump circuit. When the first boost signal is input, the second charge pump circuit operates to temporarily increase the drive capacity of the first charge pump circuit.

Embodiments described herein include radio frequency (RF) switches that may provide increased power handling capability. In general, the embodiments described herein can provide this increased power handling by equalizing the voltages across transistors when the RF switch is open. Specifically, the embodiments described herein can be implemented to equalize the source-drain voltages across each field effect transistor (FET) in a FET stack that occurs when the RF switch is open and not conducting current. This equalization can be provided by using one or more compensation circuits to couple one or more gates and transistor bodies in the FET stack in a way that at least partially compensates for the effects of parasitic leakage currents in the FET stack.

An aspect includes an apparatus including a first amplifier; a first field effect transistor (FET) including a first source coupled to an output of the first amplifier, and a first drain for coupling to a first load; and a first gate drive circuit including an input coupled to the output of the first amplifier and an output coupled to a first gate of the first FET. Another aspect includes a method including amplifying a first audio signal using a first audio amplifier to generate a first voltage; generating a first gate voltage based on the first voltage; applying the first gate voltage to a first gate of a first field effect transistor (FET) coupled between the first audio amplifier and a first audio transducer; and applying the first voltage to a first source of the first FET.

The invention relates to an electrical circuit (1) for transmitting a useful analogue signal, which has a signal transmission path (16) with an input path (2) and an output path (3) and at least one switch (6), with which the useful signal which is carried on the input path (2) can be connected through to the output path (3) or the signal transmission path (16) can be interrupted. According to the invention, a compensation circuit (4) which substantially compensates for a distortion of the useful analogue useful signal generated by the at least one switch (6) when it is switched off (OFF) is provided, wherein the compensation circuit (4) is connected to a control terminal (G) of the at least one switch (6) and comprises at least one non-linear capacitance.

An embodiment of the present disclosure relates to an electronic circuit including a first switch coupling a first node of the circuit to an input/output terminal of the circuit; a second switch coupling the first node to a second node of application of a fixed potential; and a highpass filter having an input coupled to the terminal and an output coupled to a control terminal of the second switch.

A switch circuit of an embodiment includes a radio-frequency switch and a level shifter circuit. The radio-frequency switch, which includes a first switch group and a second switch group each including a plurality of switches, switches transmission/reception of a radio-frequency signal. The level shifter circuit outputs a first signal for controlling ON/OFF of each switch of the first switch group and a second signal for controlling ON/OFF of each switch of the second switch group.

A positive-logic FET switch stack that does not require a negative bias voltage, exhibits high isolation and low insertion/mismatch loss, and may withstand high RF voltages. Embodiments include a FET stack comprising series-coupled positive-logic FETs (i.e., FETs not requiring a negative voltage supply to turn OFF), series-coupled on at least one end by an “end-cap” FET of a type that turns OFF when its V.sub.GS is zero volts. The one or more end-cap FETs provide a selectable capacitive DC blocking function or a resistive signal path. Embodiments include a stack of FETs of only the zero V.sub.GS type, or a mix of positive-logic and zero V.sub.GS type FETs with end-cap FETs of the zero V.sub.GS type. Some embodiments withstand high RF voltages by including combinations of series or parallel coupled resistor ladders for the FET gate resistors, drain-source resistors, body charge control resistors, and one or more AC coupling modules.

The switch device includes a first circuit. The first circuit has a first end coupled between a first terminal and a second terminal, and the first circuit has the second end coupled between the first terminal and the second terminal or coupled to a third terminal. The first circuit includes a first switch and a second switch. The first switch is coupled between the first end and the second end of the first circuit and is turned on or off according to a first control signal. The second switch is connected to the first switch in parallel and is turned on or off according to a second control signal. The first switch and the second switch include transistors of the same type. In a surge protection mode, the second switch is turned on to dissipate the surge current.

A semiconductor structure including a substrate, a first well, a second well, a first doped region, a second doped region, a gate electrode, an insulating layer, a field plate, and a tunable circuit is provided. The first and second wells are formed on the substrate. The first doped region is formed in the first well. The second doped region is formed in the second well. The gate electrode is disposed over the substrate. The gate electrode, the first doped region, and the second doped region constitute a transistor. The insulating layer is disposed on the substrate and overlaps the gate electrode. The field plate overlaps the insulating layer and the gate electrode. The tunable circuit provides either a first short-circuit path between the field plate and the gate electrode, or a second short-circuit path between the field plate and the first doped region.