Series-shunt-type semiconductor switching circuit

Claim 2

A series-shunt-type semiconductor switching circuit comprising: two field-effect transistors connected in a series-shunt fashion between input and output terminals of the circuit and used as switching elements; means, connected to said first and second field-effect transistors, respectively, for driving said first and second switching elements to alternately conductive and nonconductive states; a capacitor one end of which is connected to the input terminal and the other end of which is connected to the ground; and at least one impedance element provided in an electrical path from a connection point of said capacitor and the input terminal, through said first and second switching elements to the ground, said impedance element operatingly eliminating offset voltage.

Claim 3

A series-shunt-type semiconductor switching circuit according to claim 1, wherein said at least one impedance element is a resistance element connected between the source electrode of the field-effect transistor constituting said second switching element.

Claim 4

A series-shunt-type semiconductor switching circuit according to claim 2, wherein said at least one impedance element includes a series connection of two resistors, to the junction of which another resistor is connected for negative feedback of the output of an amplifier thereto.

Claim 5

A series-shunt-type semiconductor switching circuit according to claim 3, wherein said at least one impedance element further includes a capacitance element connected between said junction of the two resistors and the common one of the output terminals.

Claim 6

A series-shunt-type semiconductor switching circuit according to claim 4, wherein said at least one impedance element further includes another resistance element connected between the source electrode of the field-effect transistor constituting said first switching element and the connection point of said capacitance and the signal applied one of the input terminals of the circuit.

Claim 7

A series-shunt-type semiconductor switching circuit according to claim 1, wherein said at least one impedance element is a resistance element connected to the drain electrode of the field-effect transistor constituting said first switching element.

Claim 8

A series-shunt-type semiconductor switching circuit according to claim 6, wherein said at least one impedance element further includes another resistance element connected to the drain electrode of the field-effect transistor constituting said second switching element.

Claim 9

A series-shunt-type semiconductor switching circuit according to claim 7, wherein said resistance elements are constituted by a slidable resistor the sliding contact of which is connected to the signal taking out one of the output terminals of the circuit.

Claim 10

A semiconductor switching circuit comprising: first and second input terminals; first and second output terminals, said second input terminal and said second output terminal being connected together; means for controllably connecting said first input terminal with said first output terminal, including a first field-effect transistor connected between said first input and said first output terminal; means for controllably connecting said first output terminal with said second output terminal, including a second field-effect transistor connected between said first and second output terminals; means, connected to said first and second field-effect transistors respectively, for driving said first and second field-effect transistors into alternately conductive and nonconductive states; a first capacitor connected between said first and second input terminals; and means for substantially eliminating offset voltage; comprising at least one impedance element provided in an electrical path from said first input terminal through said first and second field-effect transistors to said seCond output terminal.

Claim 11

A semiconductor switching circuit comprising: first and second input terminals; first and second output terminals, said second input terminal and said second output terminal being connected together; means for controllably connecting said first input terminal with said first output terminal, including a first field-effect transistor connected between said first input and said first output terminal; means for controllably connecting said first output terminal with said second output terminal, including a second field-effect transistor connected between said first and second output terminals; means, connected to said first and second field-effect transistors respectively, for driving said first and second field-effect transistors into alternately conductive and nonconductive states; a first capacitor connected between said first and second input terminals; and means for substantially eliminating offset voltage; comprising at least one impedance element provided in an electrical path from said first input terminal through said first and second field-effect transistors to said seCond output terminal.