Claims
- 1. A switching circuit comprising:
- first and second power supply terminals for supplying first and second operating voltages, respectively, to said switching circuit;
- an output terminal;
- at least first to fourth input terminals for respectively receiving at least first to fourth input signals, said third and fourth input signals being reversed in phase relative to said first and second input signals;
- a current mirror coupled to have an input node for receiving an input current and to have an output node which is coupled to said output terminal and to said second power supply terminal, wherein said current mirror provides an output current at said output node thereof in response to a supply of said input current to said input node thereof so as to execute one of charging and discharging of an output capacitance of said output terminal;
- a first switching circuit coupled between said first power supply terminal and said input node of said current mirror and for providing said input current to said current mirror, wherein said first switching circuit includes at least first and second switch elements which are driven by said first and second input signals, respectively; and
- a second switching circuit coupled between said first power supply terminal and said output terminal and for executing the other of said charging and discharging of output capacitance of said output terminal, wherein said second switching circuit includes at least third and fourth switch elements which are driven by said third and fourth input signals, respectively,
- wherein said first and second switch elements are coupled in one connecting mode from among series and parallel connections between said first power supply terminal and said input node of said current mirror,
- wherein said third and fourth switch elements are in another connecting mode from among series and parallel connections between said first power supply terminal and said output terminal, and
- wherein said first and second switching circuits are selectively operated by said first to fourth input signals.
- 2. A switching circuit as defined in claim 1, wherein a signal output from said output node has a signal level different from that of said first to fourth input signals.
- 3. A switching circuit as defined in claim 1, wherein said current mirror comprises a pair of IGFETs having channels of a first conductivity type having their gates coupled to each other and to said input node and their source-drain paths coupled between said input or output node and said second power supply terminal, respectively, wherein said first to fourth switching elements are composed of IGFETs having channels of a second conductivity type coupled to have their gates coupled to said first to fourth input terminals, respectively, wherein said IGFETs having channels of a second conductivity type corresponding to said first and second switch elements are coupled to have their source-drain paths coupled between said first power supply terminal and said input node of said current mirror, and wherein said IGFETs having channels of a second conductivity type corresponding to said third and fourth switch elements are coupled to have their source-drain paths coupled between said first power supply terminal and said output terminal.
- 4. A switching circuit as defined in claim 1, further comprising:
- a first bipolar transistor operating as an emitter-follower transistor and coupled to have its collector-emitter path coupled between said first power supply terminal and said output terminal and further coupled to have its base-emitter junction coupled between said second switching circuit and said output terminal.
- 5. A switching circuit as defined in claim 4, further comprising:
- a second bipolar transistor coupled to have its collector-emitter path coupled between said output terminal and said second power supply terminal; and
- impedance means coupled between a base of said second bipolar transistor and said second power supply terminal,
- wherein said current mirror includes first and second IGFETs coupled to have their gates coupled in common and to said input node, said first IGFET being coupled to have its source-drain path coupled between said input node and said second power supply terminal, said second IGFET being coupled to have its source-drain path coupled between said output node and the base of said second bipolar transistor.
- 6. A switching circuit as defined in claim 4, further comprising:
- discharge means coupled between the base of said emitter-follower transistor and said second power supply terminal.
Priority Claims (1)
Number |
Date |
Country |
Kind |
60-292667 |
Dec 1985 |
JPX |
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Parent Case Info
This is a continuation of application Ser. No. 946,777, filed Dec. 29, 1986, and now abandoned.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
4636665 |
McLaughlin |
Jan 1987 |
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Continuations (1)
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Number |
Date |
Country |
Parent |
946777 |
Dec 1986 |
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