High speed logic circuit having output feedback

Claim 2

A logic circuit having an input and an output and powered by first and second power supplies, comprising: level-shifting means connected to said input for shifting a level of an input signal; a first series connection of a first fixed value resistor means and a first field effect device having a source, a drain and a gate, connected between said first power supply and a ground; one terminal of said first fixed value resistor means being connected to said first power supply; another terminal of said first fixed value resistor means and the drain of the first field effect device being connected together to constitute said output; the source of said first field effect device being connected to the ground; the gate of said first field effect device being connected so as to receive an output signal of said level-shifting means; a second field effect device having a source, a drain and a gate, connected between the gate of said first field effect device and said second power supply, for discharging the gate of said first field effect device; the drain of said second field effect device being connected to the gate of said first field effect device; the source of said second field effect device being connected to said second power supply; and feedback means connected between the gate of said second field effect device and said output interconnecting the drain of said first field effect transistor and said first fixed value resistor means for feeding back an output signal to the gate of said second field effect device.

Claim 3

A logic circuit having an input and an output and powered by first and second power supplies, comprising: level-shifting means connected to said input for shifting a level of an input signal; a first series connection of a first resistor means and a first field effect device having a source, a drain and a gate, connected between said first power supply and a ground; one terminal of said first resistor means being connected to said first power supply; another terminal of said first resistor means and the drain of the first field effect device being connected together to constitute said output; the source of said first field effect device being connected to the ground; the gate of said first field effect device being connected so as to receive an output signal of said level-shifting means; a second field effect device having a source, a drain and a gate, connected between the gate of said first field effect device and said second power supply, for discharging the gate of said first field effect device; the drain of said second field effect device being connected to the gate of said first field effect device; the source of said second field effect device being connected to said second power supply; and feedback means connected between the gate of said second field effect device and said output for feeding back an output signal to the gate of said second field effect device; wherein said feedback means comprises a second series connection of an impedance means and second resistor means, which are connected between said output and said ground; and an intersection of said impedance means and said second resistor means is connected to the gate of said second field effect device.

Claim 4

A logic circuit having an input and an output and powered by first and second power supplies, comprising: level-shifting means connected to said input for shifting a level of an input signal; a first series connection of a first resistor means and a first field effect device having a source, a drain and a gate, connected between said first power supply and a ground; one terminal of said first resistor means being connected to said first power supply; another terminal of said first resistor means and the drain of the first field effect device being connected together to constitute said output; the source of said first field effect device being connected to the ground; the gate of said first field effect device being connected so as to receive an output signal of said level-shifting means; a second field effect device having a source, a drain and a gate, connected between the gate of said first field effect device and said second power supply, for discharging the gate of said first field effect device; the drain of said second field effect device being connected to the gate of said first field effect device; the source of said second field effect device being connected to said second power supply; and feedback means connected between the gate of said second field effect device and said output for feeding back an output signal to the gate of said second field effect device; wherein said feedback means comprises a second series connection of an impedance means and second resistor means, which are connected between said output and said ground; and an intersection of said impedance means and said second resistor means is connected to the gate of said second field effect device.

Claim 5

A logic circuit in accordance with claim 2, wherein said impedance means comprises third resistor means.

Claim 6

A logic circuit in accordance with claim 3, wherein said third resistor means comprises first diode means for shifting the level of the output signal.

Claim 7

A logic circuit in accordance with claim 2, wherein said impedance means comprises capacitance means.

Claim 8

A logic circuit in accordance with claim 2, wherein said second resistor means comprises constant current source means for causing a constant current to flow into said impedance means.

Claim 9

A logic circuit in accordance with claim 1, wherein said first and second field effect devices comprise a metal semiconductor junction field effect device.

Claim 10

A logic circuit in accordance with claim 6, wherein said constant current source means comprises a third field effect device having a source, a drain and a gate, the drain of said third field effect device being connected to the gate of said second field effect device, and the source and the gate of said third field effect device being connected together to said ground.

Claim 11

A logic circuit in accordance with claim 1, wherein said first resistor means comprises a fourth field effect device having a source, a drain and a gate, the drain of said fourth field effect device being connected to said first power supply, and the source and the gate of said fourth field effect device being connected together to said output.

Claim 12

A logic circuit having an input and an output and powered by first and second power supplies, comprising: level-shifting means connected to said input for shifting a level of an input signal; a first series connection of a first resistor means and a first field effect device having a source, a drain and a gate, connected between said first power supply and a ground; one terminal of said first resistor means being connected to said first power supply; another terminal of said first resistor means and the drain of the first field effect device being connected together to constitute said output; the source of said first field effect device being connected to the ground; the gate of said first field effect device being connected so as to receive an output signal of said level-shifting means; a second field effect device having a source, a drain and a gate, connected between the gate of said first field effect device and said second power supply, for discharging the gate of said first field effect device; the drain of said second field effect device being connected to the gate of said first field effect device; the source of said second field effect device being connected to said second power supply; and feedback means connected between the gate of said second field effect device and said output for feeding back an output signal to the gate of said second field effect device; wherein said level-shifting means comprises second diode means connected with a polarity enabling conduction at a high-level input voltage applied to said input.

Claim 13

A logic circuit having an input and an output and powered by first and second power supplies, comprising: level-shifting means connected to said input for shifting a level of an input signal; a first series connection of a first resistor means and a first field effect device having a source, a drain and a gate, connected between said first power supply and a ground; one terminal of said first resistor means being connected to said first power supply; another terminal of said first resistor means and the drain of the first field effect device being connected together to constitute said output; the source of said first field effect device being connected to the ground; the gate of said first field effect device being connected so as to receive an output signal of said level-shifting means; a second field effect device having a source, a drain and a gate, connected between the gate of said first field effect device and said second power supply, for discharging the gate of said first field effect device; the drain of said second field effect device being connected to the gate of said first field effect device; the source of said second field effect device being connected to said second power supply; and feedback means connected between the gate of said second field effect device and said output for feeding back an output signal to the gate of said second field effect device; wherein said level-shifting means comprises second diode means connected with a polarity enabling conduction at a high-level input voltage applied to said input.

Claim 14

A logic circuit in accordance with claim 1, wherein said first and second field effect devices comprise an enhancement type transistor.

Claim 15

A logic circuit in accordance with claim 1, wherein said second field effect device comprises a depletion type transistor.

Claim 16

A logic circuit in accordance with claim 1, wherein said second power supply comprises said ground.

Claim 17

A logic circuit in accordance with claim 13, wherein said second field effect device comprises a depletion type transistor.

Claim 18

A logic circuit in accordance with claim 1, wherein said second field effect transistor comprises an n type transistor.

Claim 19

A logic circuit having an input and an output and powered by first and second power supplies, comprising: level shifting means connected to said input for shifting a level of an input signal; an output circuit performing a logic operation and containing said output and comprising a first series connection of a first fixed value resistor means and a first field effect device connected between said first power supply and a ground; one terminal of said first fixed value resistor means being connected to said first power supply; another terminal of said first resistor means and the drain of the first field effect device being connected together to constitute said output; the source of said first field effect device being connected to the ground; the gate of said first field effect device being connected so as to receive an output signal of said level-shifting means; a second field effect device having a source, a drain and a gate, connected between the gate of said first field effect device and said second power supply, for discharging the gate of said first field effect device; the drain of said second field effect device being connected to the gate of said first field effect device; the source of said second field effect device being connected to said second power supply; and feedback means connected between the gate of said second field effect device and said output interconnecting the drain of said first field effect transistor and said first fixed value resistor means for feeding back an output signal to the gate of said second field effect device.

Claim 20

A logic circuit having an input and an output and powered by first and second power supplies, comprising: level shifting means connected to said input for shifting a level of an input signal; an output circuit performing a logic operation and containing said output and comprising a first series connection of a first fixed value resistor means and a first field effect device connected between said first power supply and a ground; one terminal of said first fixed value resistor means being connected to said first power supply; another terminal of said first resistor means and the drain of the first field effect device being connected together to constitute said output; the source of said first field effect device being connected to the ground; the gate of said first field effect device being connected so as to receive an output signal of said level-shifting means; a second field effect device having a source, a drain and a gate, connected between the gate of said first field effect device and said second power supply, for discharging the gate of said first field effect device; the drain of said second field effect device being connected to the gate of said first field effect device; the source of said second field effect device being connected to said second power supply; and feedback means connected between the gate of said second field effect device and said output interconnecting the drain of said first field effect transistor and said first fixed value resistor means for feeding back an output signal to the gate of said second field effect device.

Claim 21

A logic circuit having an input and an output and powered by a power supply having first and second voltage sources and a ground, comprising: level-shifting means connected to said input for shifting a level of an input signal; a first series connection of a first fixed value resistor means and a first field effect device having a source, a drain and a gate, connected between said first power supply and the ground; one terminal of said first fixed value resistor means being connected to said first voltage source; another terminal of said first fixed value resistor means and the drain of the first field effect device being connected together to constitute said output; the source of said first field effect device being connected to the ground; the gate of said first field effect device being connected so as to receive an output current of said level-shifting means; and current control means comprising a second field effect transistor connected between said level-shifting means and said second voltage source and being responsive to an output signal at said output interconnecting the drain of said first field effect transistor and said first fixed value resistance means for controlling the output current of said level-shifting means.

Claim 22

A logic circuit having an input and an output and powered by a power supply having first and second voltage sources and a ground, comprising: level-shifting means connected to said input for shifting a level of an input signal; a first series connection of a first fixed value resistor means and a first field effect device having a source, a drain and a gate, connected between said first power supply and the ground; one terminal of said first fixed value resistor means being connected to said first voltage source; another terminal of said first fixed value resistor means and the drain of the first field effect device being connected together to constitute said output; the source of said first field effect device being connected to the ground; the gate of said first field effect device being connected so as to receive an output current of said level-shifting means; and current control means comprising a second field effect transistor connected between said level-shifting means and said second voltage source and being responsive to an output signal at said output interconnecting the drain of said first field effect transistor and said first fixed value resistance means for controlling the output current of said level-shifting means.