CMOS bootstrapped output driver method and circuit
First Claim
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1. An output driver circuit having an output pad, digital circuit inputs comprising an input signal, an inverse signal of said input signal, a control signal, and supply and ground nodes, said supply and ground nodes connectable to supply and ground potentials respectively, said digital circuit inputs having high and low logic levels, wherein the output driver circuit comprises:
- a) a push-pull transistor configuration having a pull-up transistor circuit connectable to said supply potential, said pull-up transistor circuit being a CMOS transistor arrangement, said CMOS transistor arrangement comprising serially connected NMOS and PMOS transistors, the PMOS transistor being gated by the input signal after inversion of the input signal through an inverter, the NMOS transistor gated in at least two increments by a bootstrapped configuration at a gate node, said bootstrapped configuration accepting the input signal and the inverse signal such that the NMOS and the PMOS of said CMOS receive complementary gate signals resulting in duplicate switching wherein both transistors are off when the input signal has said low logic level and both transistors are on when the input signal has said high logic level;
b) a pull-down transistor connectable to said ground potential, said pull-down transistor being an NMOS having a drain connected serially at said series connection to a source of the NMOS of said CMOS transistor arrangement and having its source connectable to said ground potential, the NMOS of said pull-down transistor gated by said control signal such that a high logic level control signal transfers a low logic level input signal to the output pad and a low logic level control signal transfers a high impedance to the output pad when said input signal has said low logic level and transfers said high logic level to the output pad when said input signal has said high logic level, said pull-up and pull-down transistors having a series connection, the output pad connected in parallel with said pull-down transistor from said series connection to said ground potential; and
c) said pull-down transistor further comprises at least two parallel connected NMOS, said parallel connected NMOS having a common source at said ground potential and a common drain at said series connection and being gated by said control signal.
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Abstract
An output driver circuit of a DRAM is wired in a push-pull arrangement. A CMOS transistor arrangement provides a strong output signal. This transistor arrangement comprises the pull-up transistor circuit of the push-pull arrangement. A bootstrap circuit gates the NMOS of the CMOS causing an incremental increase in CMOS drain current.
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Citations
41 Claims
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1. An output driver circuit having an output pad, digital circuit inputs comprising an input signal, an inverse signal of said input signal, a control signal, and supply and ground nodes, said supply and ground nodes connectable to supply and ground potentials respectively, said digital circuit inputs having high and low logic levels, wherein the output driver circuit comprises:
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a) a push-pull transistor configuration having a pull-up transistor circuit connectable to said supply potential, said pull-up transistor circuit being a CMOS transistor arrangement, said CMOS transistor arrangement comprising serially connected NMOS and PMOS transistors, the PMOS transistor being gated by the input signal after inversion of the input signal through an inverter, the NMOS transistor gated in at least two increments by a bootstrapped configuration at a gate node, said bootstrapped configuration accepting the input signal and the inverse signal such that the NMOS and the PMOS of said CMOS receive complementary gate signals resulting in duplicate switching wherein both transistors are off when the input signal has said low logic level and both transistors are on when the input signal has said high logic level; b) a pull-down transistor connectable to said ground potential, said pull-down transistor being an NMOS having a drain connected serially at said series connection to a source of the NMOS of said CMOS transistor arrangement and having its source connectable to said ground potential, the NMOS of said pull-down transistor gated by said control signal such that a high logic level control signal transfers a low logic level input signal to the output pad and a low logic level control signal transfers a high impedance to the output pad when said input signal has said low logic level and transfers said high logic level to the output pad when said input signal has said high logic level, said pull-up and pull-down transistors having a series connection, the output pad connected in parallel with said pull-down transistor from said series connection to said ground potential; and c) said pull-down transistor further comprises at least two parallel connected NMOS, said parallel connected NMOS having a common source at said ground potential and a common drain at said series connection and being gated by said control signal.
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2. An output driver circuit having an output pad, digital circuit inputs comprising an input signal, an inverse signal of said input signal, a control signal, and supply and ground nodes, said supply and ground nodes connectable to supply and ground potentials respectively, said digital circuit inputs having high and low logic levels, wherein the output driver circuit comprises:
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a) a push-pull transistor configuration having a pull-up transistor circuit connectable to said supply potential, said pull-up transistor circuit being a CMOS transistor arrangement, said CMOS transistor arrangement comprising serially connected NMOS and PMOS transistors, the PMOS transistor being gated by the input signal after inversion of the input signal through an inverter, the NMOS transistor gated in at least two increments by a bootstrapped configuration at a gate node, said bootstrapped configuration accepting the input signal and the inverse signal such that the NMOS and the PMOS of said CMOS receive complementary gate signals resulting in duplicate switching wherein both transistors are off when the input signal has said low logic level and both transistors are on when the input signal has said high logic level; b) a pull-down transistor connectable to said ground potential, said pull-down transistor being an NMOS having a drain connected serially at said series connection to a source of the NMOS of said CMOS transistor arrangement and having a source connectable to said ground potential, the NMOS of said pull-down transistor gated by said control signal such that a high logic level control signal transfers a low logic level input signal to the output pad and a low logic level control signal transfers a high impedance to the output pad when said input signal has said low logic level and transfers said high logic level to the output pad when said input signal has said high logic level, said pull-up and pull-down transistors having a series connection, the output pad connected in parallel with said pull-down transistor from said series connection to said ground potential; and c) an initial NMOS transistor pair connected serially at a serial output, having a first initial NMOS transistor gated by the input signal and a second initial NMOS transistor gated by an inverse of the input signal, said first initial NMOS transistor connectable to said supply potential at a drain, and said second initial NMOS transistor connectable to said ground potential at a source, said initial NMOS transistor pair having opposite on-off states, said high logic level on said input signal resulting in a high at said serial output, said low logic level on said input signal resettling in said low logic level at said serial output; d) a subsequent MOS transistor pair having a PMOS and an NMOS serially connected at a serial connection output, said PMOS connectable to said supply potential at a drain and said NMOS connectable to said ground potential at a source, the NMOS of said subsequent MOS transistors pair directly gated by said serial output and the PMOS of said subsequent MOS transistor pair directly gated by said input signal, the MPOS and the NMOS of said subsequent transistor pair having opposite on-off states resulting in said high logic level at said serial connection output when the input signal has said low logic level and said low logic level at the serial connection output when the input signal has said high logic level; e) a commonly gated MOS transistor pair serially connected at a serial node having a PMOS transistor connectable to said supply potential at a drain and an NMOS transistor connectable to said ground potential at a source, the PMOS and the NMOS of said commonly gated MOS transistor pair having opposite on-off states resulting in said high logic level at said serial node when said serial connecting output has said low logic level and resulting in said low logic level when said serial connection output has said high logic level, said serial connection output directly connected to the gates of said commonly gated MOS transistor pair; f) a switching NMOS transistor connected between the input signal and said gate node, said serial connection output gating said switching NMOS transistor through a continually gated NMOS transistor, said switching NMOS transistor transferring the input signal to said gate node when closed and isolating said gate node from the input signal when open; and g) a capacitor connected between said serial node and said gate node, said capacitor receiving an initial low logic level at said gate node through said switching transistor and said low logic level at said serial node when the input signal has said low logic level, said capacitor remaining at said low logic level at said serial node and going high at said gate node upon an initial firing of the input signal from said low logic level to said high logic level, said high logic level transferred to said gate node through said switching transistor, said capacitor charging to said high logic level, said gate node gating the NMOS of said CMOS, said initial firing causing said switching transistor to open after a three gate time delay, said opening isolating said gate node from the input signal, said serial node going to said high logic level after a three gate time delay after said initial firing, said high logic level boosting said capacitor to a higher potential, the NMOS of said CMOS turning on harder.
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3. An output driver circuit having an output pad, digital circuit inputs comprising an input signal, an inverse signal of said input signal, a control signal, and supply and ground nodes, said supply and ground nodes connectable to supply and ground potentials respectively, said digital circuit inputs having high and low logic levels, wherein the output driver circuit comprises:
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a) a push-pull transistor configuration having a pull-up transistor circuit connectable to said supply potential, said pull-up transistor circuit being a CMOS transistor arrangement, said CMOS transistor arrangement comprising serially connected NMOS and PMOS transistors, the PMOS transistor being gated by the input signal after inversion of the input signal through an inverter, the NMOS transistor gated in at least two increments by a bootstrapped configuration at a gate node, said bootstrapped configuration accepting the input signal and the inverse signal such that the NMOS and the PMOS of said CMOS receive complementary gate signals resulting in duplicate switching wherein both transistors are off when the input signal has said low logic level and both transistors are on when the input signal has said high logic level; b) a pull-down transistor connectable to said ground potential, said pull-down transistor being an NMOS having a drain connected serially at said series connection to a source of the NMOS of said CMOS transistor arrangement and having a source connectable to said ground potential, the NMOS of said pull-down transistor gated by said control signal such that a high logic level control signal transfers a low logic level input signal to the output pad and a low logic level control signal transfers a high impedance to the output pad when said input signal has said low logic level and transfers said high logic level to the output pad when said input signal has said high logic level, said pull-up and pull-down transistors having a series connection, the output pad connected in parallel with said pull-down transistor from said series connection to said ground potential; and c) a pull-up device for pulling said gate node to said high logic level.
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4. An output driver circuit having an output pad, digital circuit inputs comprising an input signal, an inverse signal of said input signal, a control signal, and supply and ground nodes, said supply and ground nodes connectable to supply and ground potentials respectively, said digital circuit inputs having high and low logic levels, wherein the output driver circuit comprises:
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a) a push-pull transistor configuration having a pull-up transistor circuit connectable to said supply potential, said pull-up transistor circuit being a CMOS transistor arrangement, said CMOS transistor arrangement comprising serially connected NMOS and PMOS transistors, the PMOS transistor being gated by the input signal after inversion of the input signal through an inverter, the NMOS transistor gated in at least two increments by a bootstrapped configuration at a gate node, said bootstrapped configuration accepting the input signal and the inverse signal such that the NMOS and the PMOS of said CMOS receive complementary gate signals resulting in duplicate switching wherein both transistors are off when the input signal has said low logic level and both transistors are on when the input signal has said high logic level; b) a pull-down transistor connectable to said ground potential, said pull-down transistor being an NMOS having a drain connected serially at said series connection to a source of the NMOS of said CMOS transistor arrangement and having a source connectable to said ground potential, the NMOS of said pull-down transistor gated by said control signal such that a high logic level control signal transfers a low logic level input signal to the output pad and a low logic level control signal transfers a high impedance to the output pad when said input signal has said low logic level and transfers said high logic level to the output pad when said input signal has said high logic level, said pull-up and pull-down transistors having a series connection, the output pad connected in parallel with said pull-down transistor from said series connection to said ground potential; and c) a pull-down device for pulling said control signal to said low logic level.
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5. A method of driving an input signal to an output pad in a digital circuit wherein the input signal and its inverse signal and a control signal are the digital circuit inputs, the digital circuit having supply and ground connections, said supply and ground connections connectable to supply and ground potentials respectively, said inputs having high and low logic levels, comprising:
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a) gating a CMOS pull-up transistor circuit of a push-pull output driver configuration said CMOS having serially connected PMOS and NMOS transistors, a drain of said PMOS of said CMOS connected to said supply connection, said NMOS of said CMOS having a gate, said gate having a gate node; b) gating during a first NMOS pull-down transistor of said push-pull output driver, said first NMOS pull-down transistor drain connected to a source of said NMOS of said CMOS, said first NMOS pull-down connected in parallel to said output pad; c) turning off the PMOS and the NMOS of said CMOS when the input signal has said low logic level; d) turning on the PMOS and the NMOS of said CMOS when the input signal has said high logic level; e) inverting the input signal to the gate of the PMOS of said CMOS; and f) pulling said gate node to said low logic level when a switching NMOS transistor connecting said gate node to said low input signal is gated, said gate node being connected to a capacitor, said capacitor connected between said gate node and a serial node of a serially connected commonly gated MOS transistor pair, said commonly gated MOS transistor pair comprising a PMOS having a drain connectable to said supply potential and an NMOS having a source connectable to said ground potential, said PMOS and said NMOS of said commonly gated MOS transistor pair having opposite on-off states, said NMOS being on such that said serial node has said low logic level. - View Dependent Claims (6, 7)
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8. A method of driving an input signal to an output pad in a digital circuit wherein the input signal and its inverse signal and a control signal are digital circuit inputs, the digital circuit having supply and ground connections, said supply and ground connections connectable to supply and ground potentials respectively, said inputs having high and low logic levels, comprising:
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a) gating a CMOS pull-up transistor circuit of a push-pull output driver configuration said CMOS having serially connected PMOS and NMOS transistors, a drain of said PMOS of said CMOS connected to said supply connection, said NMOS of said CMOS having a gate, said gate having a gate node; b) gating during a first NMOS pull-down transistor of said push-pull output driver, said first NMOS pull-down transistor having a drain connected to a source of said NMOS of said CMOS, said first NMOS pull-down connected in parallel to said output pad; c) turning off the PMOS and the NMOS of said CMOS when the input signal has said low logic level; d) turning on the PMOS and the NMOS of said CMOS when the input signal has said high logic level; e) inverting the input signal to the gate of the PMOS of said CMOS, said inverting turning on said PMOS; f) charging said gate node for an initial gating of the NMOS of said CMOS; g) isolating said gate node; and h) boosting a potential of said gate node, in order to gate the NMOS of said CMOS at a higher logic level than said initial gating. - View Dependent Claims (9, 10, 11)
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12. A method of driving an input signal to an output pad in a digital circuit wherein the input signal and its inverse signal and a control signal are the digital circuit inputs, the digital circuit having supply and ground connections, said supply and ground connections connectable to supply and ground potentials respectively, said inputs having high and low logic levels, comprising:
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a) gating a CMOS pull-up transistor circuit of a push-pull output driver configuration said CMOS having serially connected PMOS and NMOS transistors, a drain of said PMOS of said CMOS connected to said supply connection, said NMOS of said CMOS having a gate, said gate having a gate node; b) gating during a first NMOS pull-down transistor of said push-pull output driver, said first NMOS pull-down transistor having a drain connected to a source of said NMOS of said CMOS, said first NMOS pull-down connected in parallel to said output pad; c) turning off the PMOS and the NMOS of said CMOS when the input signal has said low logic level; d) turning on the PMOS and the NMOS of said CMOS when the input signal has said high logic level; e) pulling said gate node high when the gate node is at a high level, said pulling accomplished by a pull-up device connectable between said gate node and said supply potential.
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13. A method of driving an input signal to an output pad in a digital circuit wherein the input signal and its inverse signal and a control signal are the digital circuit inputs, the digital circuit having supply and ground connections, said supply and ground connections connectable to supply and ground potentials respectively, said inputs having high and low logic levels, comprising:
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a) gating a CMOS pull-up transistor circuit of a push-pull output driver configuration said CMOS having serially connected PMOS and NMOS transistors, a drain of said PMOS of said CMOS connected to said supply connection, said NMOS of said CMOS having a gate, said gate having a gate node; b) gating during a first NMOS pull-down transistor of said push-pull output driver, said first NMOS pull-down transistor drain connected to a source of said NMOS of said CMOS, said first NMOS pull-down connected in parallel to said output pad; c) turning off the PMOS and the NMOS of said CMOS when the input signal has said low logic level; d) turning on the PMOS and the NMOS of said CMOS when the input signal has said high logic level; e) directly gating said pull-down NMOS transistor with said control signal, a high logic level control signal transferring a low logic level input signal to the output pad and a low logic level control signal transferring a high impedance to the output pad when the input signal has said low logic level and transferring said high logic level to the output pad when the input signal has said high logic level; and f) connecting a second NMOS pull-down transistor in parallel to said first NMOS pull-down transistor and gating said second NMOS pull-down transistor with said control signal.
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14. A method of driving an input signal to an output pad in a digital circuit wherein the input signal and its inverse signal and a control signal are the digital circuit inputs, the digital circuit having supply and ground connections, said supply and ground connections connectable to supply and ground potentials respectively, said inputs having high and low logic levels, comprising:
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a) gating a CMOS pull-up transistor circuit of a push-pull output driver configuration said CMOS having serially connected PMOS and NMOS transistors, a drain of said PMOS of said CMOS connected to said supply connection, said NMOS of said CMOS having a gate, said gate having a gate node; b) gating during a first NMOS pull-down transistor of said push-pull output driver, said first NMOS pull-down transistor drain connected to a source of said NMOS of said CMOS, said first NMOS pull-down connected in parallel to said output pad; c) turning off the PMOS and the NMOS of said CMOS when the input signal has said low logic level; d) turning on the PMOS and the NMOS of said CMOS when the input signal has said high logic level; e) pulling said gate node to said low logic level when said control signal is at said low logic level, said pulling accomplished by a pull-down device connectable between said control signal and said ground potential.
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15. An output driver circuit having an output node for providing an output signal, a supply node capable of electrical communication with a supply potential, a ground node capable of electrical communication with a ground potential, and digital circuit inputs comprising an input signal and a control signal, said digital circuit inputs and said output signal capable of first and second logic levels, said first and second logic levels being voltage potentials of substantially different values, wherein the output driver circuit comprises:
a push-pull transistor configuration including; a) a pull-up transistor circuit interposed between said supply node and said output node, said pull-up transistor circuit comprising serially connected N-channel metal oxide semiconductor and P-channel metal oxide semiconductor transistors, said N-channel metal oxide semiconductor transistor being gated at a gate node by at least two voltage increments, said voltage increments provided by a bootstrap circuit, said bootstrap circuit accepting the input signal, said N-channel metal oxide semiconductor and said P-channel metal oxide semiconductor transistors receiving complementary gate signals resulting in duplicate switching of said N-channel metal oxide semiconductor and said P-channel metal oxide semiconductor transistors, wherein said P-channel metal oxide semiconductor transistor is gated by an inverse of the input signal, said N-channel metal oxide semiconductor transistor and said P-channel metal oxide semiconductor transistors being deactuated when the input signal has said second logic level and actuated when the input signal has said first logic a signal. b) a pull-down transistor interposed beaten said ground connection and said output node, said pull-down transistor being gated by said control signal; and
whereini) when said control signal has a first logic level and said input signal has said second logic level, then said output signal has said second logic level; ii) when said control signal has a second logic level and said input signal has said high logic level then said input signal has a high logic level; and iii) when said control signal has said second logic level a high impedance is felt at the output node when said input signal has said low logic level. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23)
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24. A method of driving an input signal from an input terminal to an output node in a digital circuit wherein the input signal and a control signal comprise digital circuit input signals, the digital circuit connectable to a supply potential at a supply node and connectable to a ground potential at a ground node, said digital circuit input signals capable of attaining high and low logic levels, the method comprising:
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a) controlling a pull-up transistor circuit of a push-pull circuit configuration with said input signal, said pull-up transistor circuit comprising serially connected PMOS and NMOS transistors, said controlling effecting duplicate switching states of said PMOS and NMOS transistors, said stitching states comprising a deactuated state and an actuate state, said controlling comprising actuating said NMOS transistor by applying at least two incremental voltage levels at a gate node in electrical communication with a gate terminal of said NMOS transistor, said actuating further comprising; i) charging said gate node to an initial voltage level for an initial gating of said NMOS transistor; ii) isolating said gate node; and iii) boosting said initial voltage to a higher voltage level in order to gate said NMOS transistor at a higher voltage level than said initial gating; and b) controlling a pull-down transistor of said push-pull circuit configuration with said control signal such that said pull-down transistor has a switching state, said switching state comprising actuated and deactuated states.
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25. A method of driving an input signal from an input terminal to an output node in a digital circuit wherein the input signal and a control signal comprise digital circuit input signals, the digital circuit connectable to a supply potential at a supply node and connectable to a ground potential at a ground node, said digital circuit input signals capable of attaining high and low logic levels, the method comprising:
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a) controlling a pull-up transistor circuit of a push-pull circuit configuration with said input signal, said pull-up transistor circuit comprising serially connected PMOS and NMOS transistors, said controlling comprising actuating said NMOS transistor by applying at least two incremental voltage levels at a gate node in electrical communication with a gate terminal of said NMOS transistor, said controlling effecting duplicate switching states of said PMOS and NMOS transistors, said switching states comprising a deactuated state and an actuated state, said effecting duplicating switching states of said PMOS and NMOS transistors further comprising; i) driving a signal having an inverse logic state of said input signal to a gate terminal of said PMOS transistor; ii) pulling said gate node to one of said high and low logic states of said input signal by gating a switching NMOS transistor interposed beaten said gate node and said input terminal, a capacitor interposed between said gate node and a serial node, said serial node a serial connection of a serially connected commonly gated MOS transistor pair, said commonly gated MOS transistor pair comprising a PMOS having its drain connected to said supply node and an NMOS having its source connected to said ground node, said PMOS and said NMOS of said commonly gated MOS transistors pair having opposite on-off states; and b) controlling a pull-down transistor of said push-pull circuit configuration with said control signal such that said pull-down transistor has a switching state, said switching state comprising actuated and deactuated states. - View Dependent Claims (26, 27, 28)
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29. A method of driving an input signal from an input terminal to an output node in a digital circuit wherein the input signal and a control signal comprise digital circuit input signals, the digital circuit connectable to a supply potential at a supply node and connectable to a ground potential at a ground node, said digital circuit input signals capable of attaining high and low logic levels, the method comprising:
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a) controlling a pull-up transistor circuit of a push-pull circuit configuration with said input signal, said pull-up transistor circuit comprising serially connected PMOS and NMOS transistors, said controlling effecting duplicate switching states of said PMOS and NMOS transistors, said switching states comprising a deactuated state and an actuated state, said controlling comprising actuating said NMOS transistor by applying at least two incremental voltage levels at a gate node in electrical communication with a gate terminal of said NMOS transistor; b) controlling a pull-down transistor of said push-pull circuit configuration with said control signal such that said pull-down transistor has a switching state, said switching state comprising actuated and deactuated states; and c) maintaining a potential at said gate node, said maintaining accomplished by a pull-up device connected between said gate node and said supply node.
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30. A method of driving an input signal from an input terminal to an output node in a digital circuit wherein the input signal and a control signal comprise digital circuit input signals, the digital circuit connectable to a supply potential at a supply node and connectable to a ground potential at a ground node, said digital circuit input signals capable of attaining high and low logic levels, the method comprising:
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a) controlling a pull-up transistor circuit of a push-pull circuit configuration with said input signal, said pull-up transistor circuit comprising serially connected PMOS and NMOS transistors, said controlling effecting duplicate switching states of said PMOS and NMOS transistors, said switching states comprising a deactuated state and an actuated state, said controlling comprising actuating said NMOS transistor by applying at least two incremental voltage levels at a gate node in electrical communication with a gate terminal of said NMOS transistor; b) controlling a pull-down transistor of said push-pull circuit configuration with said control signal such that said pull-down transistor has a switching state, said switching state comprising actuated and deactuated states; c) directly gating said pull-down NMOS transistor with said control signal, a high control signal transferring a low input signal to the output pad and allow control signal transferring a high impedance to the output pad when the input signal is low and transferring a high to the output pad when the input signal is high; and d) connecting a second NMOS pull-down transistor in parallel to said first NMOS pull-down transistor and gating said second NMOS pull-up transistor with said control signal.
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31. A method of driving an input signal from an input terminal to an output node in a digital circuit wherein the input signal and a control signal comprise digital circuit input signals, the digital circuit connectable to a supply potential at a supply node and connectable to a ground potential at a ground node, said digital circuit input signals capable of attaining high and low logic levels, the method comprising:
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a) controlling a pull-up transistor circuit of a push-pull circuit configuration with said input signal, said pull-up transistor circuit comprising serially connected PMOS and NMOS transistors, said controlling effecting duplicate switching states of said PMOS and NMOS transistors, said switching states comprising a deactuated state and an actuated state, said controlling comprising actuating said NMOS transistor by applying at least two incremental voltage levels at a gate node in electrical communication with a gate terminal of said NMOS transistor; b) controlling a pull-down transistor of said push-pull circuit configuration with said control signal such that said pull-down transistor has a switching state, said switching state comprising actuated and deactuated states; and c) maintaining a potential at said gate node, said maintaining accomplished by a pull-up device electrically interposed between said control signal and ground.
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32. A method of driving an input signal from an input terminal to an output node in a digital circuit wherein the input signal and a control signal comprise digital circuit input signals, the digital circuit connectable to a supply potential at a supply node and connectable to a ground potential at a ground node, said digital circuit input signals capable of attaining high and low logic levels, the method comprising:
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a) controlling a pull-up transistor circuit of a push-pull circuit configuration with said input signal, said pull-up transistor circuit comprising serially connected PMOS and NMOS transistors, said controlling effecting duplicate switching states of said PMOS and NMOS transistors, said switching states comprising a deactuated state and an actuated state, said controlling comprising actuating said NMOS transistor by applying at least two incremental voltage levels at a gate node in electrical communication with a gate terminal of said NMOS transistor; and b) controlling a pull-down transistor of said push-pull circuit configuration with said control signal such that said pull-down transistor has a switching state, said switching state comprising actuated and deactuated states. - View Dependent Claims (33, 34, 35, 36, 37, 38, 39)
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40. A method of driving an input signal from an input terminal to an output node in a digital circuit wherein the input signal and a control signal comprise digital circuit input signals, the digital circuit connectable to a supply potential at a supply node and connectable to a ground potential at a ground node, said digital circuit input signals capable of attaining high and low logic levels, the method comprising:
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a) controlling a pull-up transistor circuit of a push-pull circuit configuration with said input signal, said pull-up transistor circuit comprising serially connected PMOS and NMOS transistors, said controlling effecting duplicate switching states of said PMOS and NMOS transistors, said switching states comprising a deactuated state and an actuated state, said controlling comprising actuating said NMOS transistor by applying at least two incremental voltage levels at a gate node in electrical communication with a gate terminal of said NMOS transistor; b) controlling a pull-down transistor of said push-pull circuit configuration with said control signal such that said pull-down transistor has a switching state, said switching state comprising actuated and deactuated states; and c) directly gating said pull-down NMOS transistor with said control signal a high control signal transferring a low input signal to the output pad and a low control signal transferring a high impedance to the output pad when the input signal is low and transferring a high to the output pad when the input signal is higher. - View Dependent Claims (41)
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Specification