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US 5,206,546 AGranted
Logic circuit including variable impedance means
AssigneeHitachi, Ltd.
InventorMitsuo Usami
Life of this patent
Estimating the term…
Abstract
A SPL (or Super Push-pull Logic) circuit is provided which includes: a first variable resistor circuit connected between the collector of an input transistor and a first supply voltage terminal (GND) a second variable resistor circuit connected between the emitter of the input transistor and a second supply voltage terminal (V.sub.EE) and a push-pull output circuit. The second variable resistor circuit includes an N-channel MOSFET which has its gate electrode made receptive of any of the output signals of the SPL circuit, a differentiated signal of the output signal, and an inverted signal of the input signal.
Claims32
A logic circuit comprising:
- first and second terminals for receiving first and second supply voltages, respectively;
- a first input terminal for receiving an input signal;
- an output terminal;
- a first input bipolar transistor having a base coupled to receive the input signal, a collector and an emitter;
- first variable impedance means coupled between the first terminal and the collector of the first input bipolar transistor and responsive to the input signal and for changing its impedance thereof;
- second variable impedance means coupled between the emitter of the first input bipolar transistor and the second terminal and for changing its impedance thereof in response to an output signal on the output terminal;
- an output bipolar transistor having a base coupled to the collector of the first input bipolar transistor and an emitter-collector path coupled between the first terminal and the output terminal;
- and
- pull-down means coupled between the output terminal and the second terminal and responsive to an emitter signal on the emitter of the first input bipolar transistor and for pulling down a voltage on the output terminal.
6 more elements
A logic circuit comprising:
- first and second terminals for receiving first and second supply voltages, respectively;
- a first input terminal for receiving an input signal;
- an output terminal;
- a first input bipolar transistor having a base coupled to receive the input signal, a collector and an emitter;
- a differentiation circuit coupled to the output terminal;
- first variable impedance means coupled between the first terminal and the collector of the first input bipolar transistor and responsive to the input signal and for changing its impedance;
- second variable impedance means coupled between the emitter of the first input bipolar transistor and the second terminal and for changing its impedance in response to an output signal of the differentiation circuit;
- an output bipolar transistor having a base coupled to the collector of the first input bipolar transistor and an emitter-collector path coupled between the first terminal and the output terminal;
- and
- pull-down means coupled between the output terminal and the second terminal and responsive to an emitter signal on the emitter of the first input bipolar transistor and for pulling down a voltage on the output terminal.
7 more elements
A logic circuit comprising:
- first and second terminals for receiving first and second supply voltages, respectively;
- a first input terminal for receiving a first input signal;
- a second input terminal for receiving a second input signal reversed relative to the first input signal;
- an output terminal;
- a first input bipolar transistor having a base coupled to receive the input signal, a collector and an emitter;
- first variable impedance means coupled between the first terminal and the collector of the first input bipolar transistor and responsive to the first input signal and for changing its impedance
- second variable impedance means coupled between the emitter of the first input bipolar transistor and the second terminal and for changing its impedance in response to the second input signal;
- an output bipolar transistor having a base coupled to the collector of the first input bipolar transistor and an emitter-collector path coupled between the first terminal and the output terminal;
- and
- pull-down means coupled between the output terminal and the second terminal and responsive to an emitter signal on the emitter of the first input bipolar transistor and for pulling down a voltage on the output terminal.
7 more elements
Dependencies are inferred from the claim text.