Three-terminal operational amplifier and applications thereof

Claim 2

In an operational amplifier having inverting and non-inverting input terminals for receiving respective externally supplied input signals, an output terminal for providing an amplified output, and a circuit urging said inverting and non-inverting inputs towards a common voltage level, the improvement comprising: a third input terminal for receiving an externally supplied input current signal to said operational amplifier, and circuit means for adding a second current which matches said input current signal and is inverted with respect thereto to a current supplied from said inverting input terminal, and for urging said third input terminal toward a common voltage level with said inverting and non-inverting input terminals.

Claim 3

The operational amplifier of claim 1, said operational amplifier being configured to present low input impedances to said inverting and third terminals, and a high input impedance to said non-inverting terminal.

Claim 4

The operational amplifier of claim 1, said circuit means providing said second current with a substantially unity gain with respect to said input current signal.

Claim 5

A three-terminal operational amplifier, comprising: a first operational amplifier having inverting and non-inverting inputs for receiving externally supplied input signals, and an output for supplying an amplified output, a second operational amplifier having a current input for receiving an externally supplied input current signal, a second input connected in common with one of the inputs to said first operational amplifier, and an output that is passively decoupled from the non-inverting input for said first operational amplifier, a first resistive feedback circuit connected between the output of one of said operational amplifiers and the inverting input of said first operational amplifier, a second resistive feedback circuit connected between the output of said one operational amplifier and the current input to said second operational amplifier, and an output terminal at the output of the operational amplifier which is not connected to said feedback circuits.

Claim 6

A three-terminal operational amplifier, comprising: a first operational amplifier having inverting and non-inverting inputs for receiving externally supplied input signals, and an output for supplying an amplified output, a second operational amplifier having a current input for receiving an externally supplied input current signal, a second input connected in common with one of the inputs to said first operational amplifier, and an output that is passively decoupled from the non-inverting input for said first operational amplifier, a first resistive feedback circuit connected between the output of one of said operational amplifiers and the inverting input of said first operational amplifier, a second resistive feedback circuit connected between the output of said one operational amplifier and the current input to said second operational amplifier, and an output terminal at the output of the operational amplifier which is not connected to said feedback circuits.

Claim 7

The three-terminal operational amplifier of claim 4, in which said feedback circuits are configured to subtract from said inverting input a current which is matched with the input current to said current input.

Claim 8

The three-terminal operational amplifier of claim 5, in which said feedback circuits are configured to subtract from said inverting input a current which has a substantially unity gain with respect to the input current to said current input.

Claim 9

The three-terminal operational amplifier of claim 4, wherein said first and second operational amplifiers are mutually discrete.

Claim 10

The three-terminal operational amplifier of claim 4, wherein said current input is connected to a non-inverting input of said second operational amplifier, the first operational amplifier's inverting input is connected in common with an inverting input of said second operational amplifier, said first feedback circuit is connected between the output of said first operational amplifier and its inverting input, and said second feedback circuit is connected between the output of said first operational amplifier and the current input to said second operational amplifier.

Claim 11

The three-terminal operational amplifier of claim 4, said first and second feedback circuits comprising respective resistor circuits.

Claim 12

A three-terminal operational amplifier, comprising: a first operational amplifier having inverting and non-inverting inputs, and an output, a second operational amplifier having a current input, a second input connected in common with one of the inputs to said first operational amplifier, and an output, a first feedback circuit connected between the output of one of said operational amplifiers and the inverting input of said first operational amplifier, a second feedback circuit connected between the output of said one operational amplifier and the current input to said second operational amplifier, and an output terminal at the output of the operational amplifier which is not connected to said feedback circuits, said current input being connected to an inverting input of said second operational amplifier, the first operational amplifier's non-inverting input being connected in common with a non-inverting input of said second operational amplifier, said first feedback circuit being connected between the output of said second operational amplifier and the inverting input of said first operational amplifier, and said second feedback circuit being connected between the output of said second operational amplifier and its current input.

Claim 13

A three-terminal operational amplifier, comprising: a first operational amplifier having inverting and non-inverting inputs, and an output, a second operational amplifier having a current input, a second input connected in common with one of the inputs to said first operational amplifier, and an output, a first feedback circuit connected between the output of one of said operational amplifiers and the inverting input of said first operational amplifier, a second feedback circuit connected between the output of said one operational amplifier and the current input to said second operational amplifier, and an output terminal at the output of the operational amplifier which is not connected to said feedback circuits, said current input being connected to an inverting input of said second operational amplifier, the first operational amplifier's non-inverting input being connected in common with a non-inverting input of said second operational amplifier, said first feedback circuit being connected between the output of said second operational amplifier and the inverting input of said first operational amplifier, and said second feedback circuit being connected between the output of said second operational amplifier and its current input.

Claim 14

A three-terminal operational amplifier, comprising: a first operational amplifier having inverting and non-inverting inputs, and an output, a second operational amplifier having a current input, a second input connected in common with one of the inputs to said first operational amplifier, and an output, a first nonlinear feedback circuit connected between the output of one of said operational amplifiers and the inverting input of said first operational amplifier, a second nonlinear feedback circuit connected between the output of said one operational amplifier and the current input to said second operational amplifier, and an output terminal at the output of the operational amplifier which is not connected to said feedback circuits.

Claim 15

A three-terminal operational amplifier, comprising: a first operational amplifier having inverting and non-inverting inputs, and an output, a second operational amplifier having a current input, a second input connected in common with one of the inputs to said first operational amplifier, and an output, a first nonlinear feedback circuit connected between the output of one of said operational amplifiers and the inverting input of said first operational amplifier, a second nonlinear feedback circuit connected between the output of said one operational amplifier and the current input to said second operational amplifier, and an output terminal at the output of the operational amplifier which is not connected to said feedback circuits.

Claim 16

A summing amplifier, comprising: a) a three-terminal operational amplifier, comprising: 1) an inverting input terminal, 2) a non-inverting input terminal, 3) an output terminal, 4) a circuit urging said inverting and non-inverting terminals toward a common voltage level, 5) a current input terminal for supplying a current input, and 6) circuit means for adding a current which matches said current input and is inverted with respect thereto to the input current supplied by said inverting input terminal, and for urging said current input terminal toward a common voltage level with said inverting and non-inverting input terminals, b) a feedback resistor connected between said output terminal and said inverting input terminal, c) a plurality of summing inputs connected across respective summing input resistors to said inverting input terminal to produce an inverted summed signal at said output terminal, and d) at least one additional summing input connected across respective additional summing input resistors to said current input terminal to produce a non-inverted summed signal which accumulates with said inverted summed signal at said output terminal.

Claim 17

A summing amplifier, comprising: a) a three-terminal operational amplifier, comprising: 1) an inverting input terminal, 2) a non-inverting input terminal, 3) an output terminal, 4) a circuit urging said inverting and non-inverting terminals toward a common voltage level, 5) a current input terminal for supplying a current input, and 6) circuit means for adding a current which matches said current input and is inverted with respect thereto to the input current supplied by said inverting input terminal, and for urging said current input terminal toward a common voltage level with said inverting and non-inverting input terminals, b) a feedback resistor connected between said output terminal and said inverting input terminal, c) a plurality of summing inputs connected across respective summing input resistors to said inverting input terminal to produce an inverted summed signal at said output terminal, and d) at least one additional summing input connected across respective additional summing input resistors to said current input terminal to produce a non-inverted summed signal which accumulates with said inverted summed signal at said output terminal.

Claim 18

A summing amplifier, comprising: a) a three-terminal operational amplifier, comprising: 1) a first operational amplifier having inverting and non-inverting inputs and an output, 2) a second operational amplifier having a current input, a second input connected in common with one of the inputs to said first operational amplifier, and an output, 3) a first feedback circuit connected between the output of one of said operational amplifiers and the inverting input of said first operational amplifier, 4) a second feedback circuit connected between the output of said one operational amplifier and the current input to said second operational amplifier, and 5) an output terminal at the output of the operational amplifier which is not connected to said feedback circuits, b) a feedback resistor connected between said output terminal and said inverting input, c) a plurality of summing inputs connected across respective summing input resistors to said inverting input to produce inverted summed signal at said output terminal, and d) at least one additional summing input connected across respective additional summing input resistors to said current input to produce a non-inverted summed signal which accumulates with said inverted summed signal at said output terminal.

Claim 19

A summing amplifier, comprising: a) a three-terminal operational amplifier, comprising: 1) a first operational amplifier having inverting and non-inverting inputs and an output, 2) a second operational amplifier having a current input, a second input connected in common with one of the inputs to said first operational amplifier, and an output, 3) a first feedback circuit connected between the output of one of said operational amplifiers and the inverting input of said first operational amplifier, 4) a second feedback circuit connected between the output of said one operational amplifier and the current input to said second operational amplifier, and 5) an output terminal at the output of the operational amplifier which is not connected to said feedback circuits, b) a feedback resistor connected between said output terminal and said inverting input, c) a plurality of summing inputs connected across respective summing input resistors to said inverting input to produce inverted summed signal at said output terminal, and d) at least one additional summing input connected across respective additional summing input resistors to said current input to produce a non-inverted summed signal which accumulates with said inverted summed signal at said output terminal.

Claim 20

An inverting gain amplifier, comprising: a) a three-terminal operational amplifier, comprising: 1) an inverting input terminal for receiving an externally supplied input signal, 2) a non-inverting input terminal for receiving an externally supplied input signal, 3) an output terminal for providing an amplified output, 4) a circuit urging said inverting and non-inverting input terminals toward a common voltage level, 5) a current input terminal for providing an externally supplied current input, and 6) circuit means for adding a current which matches said current input and is inverted with respect thereto to the input current supplied by said inverting input terminal, and for urging said current input terminal toward a common voltage level with said inverting and non-inverting input terminals, b) a first resistor connected between said output terminal and said inverting input terminal, and c) a second resistor connected between said current input terminal and a voltage reference, said inverting gain amplifier inverting and amplifying an input voltage signal at said non-inverting input terminal in accordance with the relative resistance values of said first and second resistors.

Claim 21

An inverting gain amplifier, comprising: a) a three-terminal operational amplifier, comprising: 1) an inverting input terminal for receiving an externally supplied input signal, 2) a non-inverting input terminal for receiving an externally supplied input signal, 3) an output terminal for providing an amplified output, 4) a circuit urging said inverting and non-inverting input terminals toward a common voltage level, 5) a current input terminal for providing an externally supplied current input, and 6) circuit means for adding a current which matches said current input and is inverted with respect thereto to the input current supplied by said inverting input terminal, and for urging said current input terminal toward a common voltage level with said inverting and non-inverting input terminals, b) a first resistor connected between said output terminal and said inverting input terminal, and c) a second resistor connected between said current input terminal and a voltage reference, said inverting gain amplifier inverting and amplifying an input voltage signal at said non-inverting input terminal in accordance with the relative resistance values of said first and second resistors.

Claim 22

An inverting gain amplifier, comprising: a) a three-terminal operational amplifier, comprising: 1) a first operational amplifier having inverting and non-inverting inputs for receiving respective externally supplied input signals, and an output for providing an amplified output, 2) a second operational amplifier having a current input for receiving an externally supplied input current, a second input connected in common with one of the inputs to said first operational amplifier, and an output that is passively decoupled from said non-inverting input, said second operational amplifier being connected to urge said current input towards a common voltage level with said inverting and non-inverting inputs, 3) a first resistive feedback circuit connected between the output of one of said operational amplifiers and the inverting input of said first operational amplifier, 4) a second resistive feedback circuit connected between the output of said one operational amplifier and the current input to said second operational amplifier, and 5) an output terminal at the output of the operational amplifier which is not connected to said feedback circuits, b) a first resistor connected between said output terminal and said inverting input, and c) a second resistor connected between said current input and a voltage reference, said inverting gain amplifier inverting and amplifying an input voltage signal at said non-inverting input in accordance with the relative resistance values of said first and second resistors.

Claim 23

An inverting gain amplifier, comprising: a) a three-terminal operational amplifier, comprising: 1) a first operational amplifier having inverting and non-inverting inputs for receiving respective externally supplied input signals, and an output for providing an amplified output, 2) a second operational amplifier having a current input for receiving an externally supplied input current, a second input connected in common with one of the inputs to said first operational amplifier, and an output that is passively decoupled from said non-inverting input, said second operational amplifier being connected to urge said current input towards a common voltage level with said inverting and non-inverting inputs, 3) a first resistive feedback circuit connected between the output of one of said operational amplifiers and the inverting input of said first operational amplifier, 4) a second resistive feedback circuit connected between the output of said one operational amplifier and the current input to said second operational amplifier, and 5) an output terminal at the output of the operational amplifier which is not connected to said feedback circuits, b) a first resistor connected between said output terminal and said inverting input, and c) a second resistor connected between said current input and a voltage reference, said inverting gain amplifier inverting and amplifying an input voltage signal at said non-inverting input in accordance with the relative resistance values of said first and second resistors.

Claim 24

An instrumentation amplifier, comprising: a) a three-terminal operational amplifier, comprising: 1) an inverting input terminal, 2) a non-inverting input terminal, 3) an output terminal, 4) a circuit urging said inverting and non-inverting terminals toward a common voltage level, 5) a current input terminal for supplying a current input, and 6) circuit means for adding a current which matches said current input and is inverted with respect thereto to the input current supplied by said inverting input terminal, and for urging said current input terminal toward a common voltage level with said inverting and non-inverting input terminals, b) a first resistor connected between said output terminal and said inverting input terminal, c) a second resistor connected between said current input and a voltage reference, d) a two-terminal operational amplifier having an inverting input, a non-inverting input, an output, and a feedback circuit connected between its output and its inverting input, and e) a third resistor connected between the output of said two-terminal operational amplifier and the inverting input of said three-terminal operational amplifier, said instrumentation amplifier producing an output voltage relative to said voltage reference in accordance with the values of respective input voltages applied to the non-inverting inputs of said two-terminal and three-terminal operational amplifiers and the relative resistance values of said first and third resistors.

Claim 25

An instrumentation amplifier, comprising: a) a three-terminal operational amplifier, comprising: 1) an inverting input terminal, 2) a non-inverting input terminal, 3) an output terminal, 4) a circuit urging said inverting and non-inverting terminals toward a common voltage level, 5) a current input terminal for supplying a current input, and 6) circuit means for adding a current which matches said current input and is inverted with respect thereto to the input current supplied by said inverting input terminal, and for urging said current input terminal toward a common voltage level with said inverting and non-inverting input terminals, b) a first resistor connected between said output terminal and said inverting input terminal, c) a second resistor connected between said current input and a voltage reference, d) a two-terminal operational amplifier having an inverting input, a non-inverting input, an output, and a feedback circuit connected between its output and its inverting input, and e) a third resistor connected between the output of said two-terminal operational amplifier and the inverting input of said three-terminal operational amplifier, said instrumentation amplifier producing an output voltage relative to said voltage reference in accordance with the values of respective input voltages applied to the non-inverting inputs of said two-terminal and three-terminal operational amplifiers and the relative resistance values of said first and third resistors.

Claim 26

An instrumentation amplifier, comprising: a) a three-terminal operational amplifier, comprising: 1) a first operational amplifier having inverting and non-inverting inputs and an output, 2) a second operational amplifier having a current input, a second input connected in common with one of the inputs to said first operational amplifier, and an output, 3) a first feedback circuit connected between the output of one of said operational amplifiers and the inverting input of said first operational amplifier, 4) a second feedback circuit connected between the output of said one operational amplifier and the current input to said second operational amplifier, and 5) an output terminal at the output of the operational amplifier which is not connected to said feedback circuits, b) a first resistor connected between said output terminal and said inverting input terminal, c) a second resistor connected between said current input and a voltage reference, d) a two-terminal operational amplifier having an inverting input, a non-inverting input, an output, and a feedback circuit connected between its output and its inverting input, and e) a third resistor connected between the output of said two-terminal operational amplifier and the inverting input of said three-terminal operational amplifier, said instrumentation amplifier producing an output voltage relative to said voltage reference in accordance with the values of respective input voltages applied to the non-inverting inputs of said two-terminal and three-terminal operational amplifiers and the relative resistance values of said first and third resistors.

Claim 27

An instrumentation amplifier, comprising: a) a three-terminal operational amplifier, comprising: 1) a first operational amplifier having inverting and non-inverting inputs and an output, 2) a second operational amplifier having a current input, a second input connected in common with one of the inputs to said first operational amplifier, and an output, 3) a first feedback circuit connected between the output of one of said operational amplifiers and the inverting input of said first operational amplifier, 4) a second feedback circuit connected between the output of said one operational amplifier and the current input to said second operational amplifier, and 5) an output terminal at the output of the operational amplifier which is not connected to said feedback circuits, b) a first resistor connected between said output terminal and said inverting input terminal, c) a second resistor connected between said current input and a voltage reference, d) a two-terminal operational amplifier having an inverting input, a non-inverting input, an output, and a feedback circuit connected between its output and its inverting input, and e) a third resistor connected between the output of said two-terminal operational amplifier and the inverting input of said three-terminal operational amplifier, said instrumentation amplifier producing an output voltage relative to said voltage reference in accordance with the values of respective input voltages applied to the non-inverting inputs of said two-terminal and three-terminal operational amplifiers and the relative resistance values of said first and third resistors.

Claim 28

An integrator circuit, comprising: a) a three-terminal operational amplifier, comprising: 1) an inverting input terminal, 2) a non-inverting input terminal, 3) an output terminal, 4) a circuit urging said inverting and non-inverting terminals toward a common voltage level, 5) a current input terminal for supplying a current input, and 6) circuit means for adding a current which matches said current input and is inverted with respect thereto to the input current supplied by said inverting input terminal, and for urging said current input terminal toward a common voltage level with said inverting and non-inverting input terminals, b) a first capacitor between said output and inverting input terminals, c) a first resistor connected between said inverting input and a voltage reference, and d) a second capacitor connected between said current input and said voltage reference, said integrator circuit integrating an input voltage signal at said non-inverting input in accordance with the values of said first and second capacitors and said first resistor.

Claim 29

An integrator circuit, comprising: a) a three-terminal operational amplifier, comprising: 1) an inverting input terminal, 2) a non-inverting input terminal, 3) an output terminal, 4) a circuit urging said inverting and non-inverting terminals toward a common voltage level, 5) a current input terminal for supplying a current input, and 6) circuit means for adding a current which matches said current input and is inverted with respect thereto to the input current supplied by said inverting input terminal, and for urging said current input terminal toward a common voltage level with said inverting and non-inverting input terminals, b) a first capacitor between said output and inverting input terminals, c) a first resistor connected between said inverting input and a voltage reference, and d) a second capacitor connected between said current input and said voltage reference, said integrator circuit integrating an input voltage signal at said non-inverting input in accordance with the values of said first and second capacitors and said first resistor.

Claim 30

The integrator circuit of claim 18, wherein said first and second capacitors have substantially equal values of capacitance.

Claim 31

An integrator circuit, comprising: a) a three-terminal operational amplifier, comprising: 1) a first operational amplifier having inverting and non-inverting inputs and an output, 2) a second operational amplifier having a current input, a second input connected in common with one of the inputs to said first operational amplifier, and an output, 3) a first feedback circuit connected between the output of one of said operational amplifiers and the inverting input of said first operational amplifier, 4) a second feedback circuit connected between the output of said one operational amplifier and the current input to said second operational amplifier, and 5) an output terminal at the output of the operational amplifier which is not connected to said feedback circuits, b) a first capacitor connected between said output and inverting input terminals, c) a first resistor connected between said inverting input and a voltage reference, and d) a second capacitor connected between said current input and said voltage reference, said integrator circuit integrating an input voltage signal at said non-inverting input in accordance with the values of said first and second capacitors and said first resistor.

Claim 32

An integrator circuit, comprising: a) a three-terminal operational amplifier, comprising: 1) a first operational amplifier having inverting and non-inverting inputs and an output, 2) a second operational amplifier having a current input, a second input connected in common with one of the inputs to said first operational amplifier, and an output, 3) a first feedback circuit connected between the output of one of said operational amplifiers and the inverting input of said first operational amplifier, 4) a second feedback circuit connected between the output of said one operational amplifier and the current input to said second operational amplifier, and 5) an output terminal at the output of the operational amplifier which is not connected to said feedback circuits, b) a first capacitor connected between said output and inverting input terminals, c) a first resistor connected between said inverting input and a voltage reference, and d) a second capacitor connected between said current input and said voltage reference, said integrator circuit integrating an input voltage signal at said non-inverting input in accordance with the values of said first and second capacitors and said first resistor.

Claim 33

The integrator circuit of claim 20, wherein said first and second capacitors having substantially equal values of capacitance.

Claim 34

A differentiator circuit, comprising: a) a three-terminal operational amplifier, comprising: 1) an inverting input terminal, 2) a non-inverting input terminal, 3) an output terminal, 4) a circuit urging said inverting and non-inverting terminals toward a common voltage level, 5) a current input terminal for supplying a current input, and 6) circuit means for adding a current which matches said current input and is inverted with respect thereto to the input current supplied by said inverting input terminal, and for urging said current input terminal toward a common voltage level with said inverting and non-inverting input terminals, b) a first resistor connected between said output and inverting input terminals, c) a first capacitor connected between said inverting input and a voltage reference, and d) a second resistor connected between said current input and said voltage reference, said differentiator circuit differentiating an input voltage signal at said non-inverting input in accordance with the values of said first and second resistors and said first capacitor.

Claim 35

A differentiator circuit, comprising: a) a three-terminal operational amplifier, comprising: 1) an inverting input terminal, 2) a non-inverting input terminal, 3) an output terminal, 4) a circuit urging said inverting and non-inverting terminals toward a common voltage level, 5) a current input terminal for supplying a current input, and 6) circuit means for adding a current which matches said current input and is inverted with respect thereto to the input current supplied by said inverting input terminal, and for urging said current input terminal toward a common voltage level with said inverting and non-inverting input terminals, b) a first resistor connected between said output and inverting input terminals, c) a first capacitor connected between said inverting input and a voltage reference, and d) a second resistor connected between said current input and said voltage reference, said differentiator circuit differentiating an input voltage signal at said non-inverting input in accordance with the values of said first and second resistors and said first capacitor.

Claim 36

The differentiator circuit of claim 22, wherein said first and second resistors have substantially equal values of resistance.

Claim 37

A differentiator circuit, comprising: a) a three-terminal operational amplifier, comprising: 1) a first operational amplifier having inverting and non-inverting inputs and an output, 2) a second operational amplifier having a current input, a second input connected in common with one of the inputs to said first operational amplifier, and an output, 3) a first feedback circuit connected between the output of one of said operational amplifiers and the inverting input of said first operational amplifier, 4) a second feedback circuit connected between the output of said one operational amplifier and the current input to said second operational amplifier, and 5) an output terminal at the output of the operational amplifier which is not connected to said feedback circuits, b) a first resistor connected between said output and inverting input terminals, c) a first capacitor connected between said inverting input and a voltage reference, and d) a second resistor connected between said current input and said voltage reference, said differentiator circuit differentiating an input voltage signal at said non-inverting input in accordance with the values of said first and second resistors and said first capacitor.

Claim 38

A differentiator circuit, comprising: a) a three-terminal operational amplifier, comprising: 1) a first operational amplifier having inverting and non-inverting inputs and an output, 2) a second operational amplifier having a current input, a second input connected in common with one of the inputs to said first operational amplifier, and an output, 3) a first feedback circuit connected between the output of one of said operational amplifiers and the inverting input of said first operational amplifier, 4) a second feedback circuit connected between the output of said one operational amplifier and the current input to said second operational amplifier, and 5) an output terminal at the output of the operational amplifier which is not connected to said feedback circuits, b) a first resistor connected between said output and inverting input terminals, c) a first capacitor connected between said inverting input and a voltage reference, and d) a second resistor connected between said current input and said voltage reference, said differentiator circuit differentiating an input voltage signal at said non-inverting input in accordance with the values of said first and second resistors and said first capacitor.

Claim 39

The differentiator circuit of claim 24, wherein said first and second resistors have substantially equal values of resistance.

Claim 40

A three-terminal operational amplifier, comprising: a composite operational amplifier having inverting, non-inverting and current inputs for receiving respective externally supplied signals, said inverting and non-inverting inputs being connected as inputs in a first two-terminal operational amplifier configuration within said composite operational amplifier, and said current input together with one of said inverting and non-inverting inputs being connected as inputs to a second two-terminal operational amplifier configuration within said composite operational amplifier, said first and second two-terminal operational amplifier configurations having respective outputs, said second two-terminal operational amplifier configuration urging said current input toward a common voltage level with said inverting and non-inverting inputs, the output of said second two-terminal operational amplifier configuration being passively decoupled from said non-inverting input, a first resistive feedback circuit connected between the output of one of said two-terminal operational amplifier configurations and said inverting input, a second resistive feedback circuit connected between the output of said one two-terminal operational amplifier configuration and said current input, and the output of the other of said two-terminal operational amplifier configurations providing an output for said composite operational amplifier which is not connected to said feedback circuits.

Claim 41

A three-terminal operational amplifier, comprising: a composite operational amplifier having inverting, non-inverting and current inputs for receiving respective externally supplied signals, said inverting and non-inverting inputs being connected as inputs in a first two-terminal operational amplifier configuration within said composite operational amplifier, and said current input together with one of said inverting and non-inverting inputs being connected as inputs to a second two-terminal operational amplifier configuration within said composite operational amplifier, said first and second two-terminal operational amplifier configurations having respective outputs, said second two-terminal operational amplifier configuration urging said current input toward a common voltage level with said inverting and non-inverting inputs, the output of said second two-terminal operational amplifier configuration being passively decoupled from said non-inverting input, a first resistive feedback circuit connected between the output of one of said two-terminal operational amplifier configurations and said inverting input, a second resistive feedback circuit connected between the output of said one two-terminal operational amplifier configuration and said current input, and the output of the other of said two-terminal operational amplifier configurations providing an output for said composite operational amplifier which is not connected to said feedback circuits.

Claim 42

A summing amplifier, comprising: a) a three-terminal operational amplifier comprising: 1) a composite operational amplifier having inverting, non-inverting and current inputs, said inverting and non-inverting inputs being connected as inputs in a first two-terminal operational amplifier configuration within said composite operational amplifier, and said current input together with one of said inverting and non-inverting inputs being connected as inputs to a second two-terminal operational amplifier configuration within said composite operational amplifier, said first and second two-terminal operational amplifier configurations having respective outputs, 2) a first feedback circuit connected between the output of one of said two-terminal operational amplifier configurations and said inverting input, 3) a second feedback circuit connected between the output of said one two-terminal operational amplifier configuration and said current input, and 4) the output of the other of said two-terminal operational amplifier configurations providing an output for said composite operational amplifier which is not connected to said feedback circuits, b) a feedback resistor connected between said composite operational amplifier output and said inverting input, c) a plurality of summing inputs connected across respective summing input resistors to said inverting input to produce an inverted summed signal at said composite operational amplifier output, and d) at least one additional summing input connected across respective additional summing input resistors to said current input to produce a non-inverted summed signal which accumulates with said inverted summed signal at said composite operational amplifier output.

Claim 43

A summing amplifier, comprising: a) a three-terminal operational amplifier comprising: 1) a composite operational amplifier having inverting, non-inverting and current inputs, said inverting and non-inverting inputs being connected as inputs in a first two-terminal operational amplifier configuration within said composite operational amplifier, and said current input together with one of said inverting and non-inverting inputs being connected as inputs to a second two-terminal operational amplifier configuration within said composite operational amplifier, said first and second two-terminal operational amplifier configurations having respective outputs, 2) a first feedback circuit connected between the output of one of said two-terminal operational amplifier configurations and said inverting input, 3) a second feedback circuit connected between the output of said one two-terminal operational amplifier configuration and said current input, and 4) the output of the other of said two-terminal operational amplifier configurations providing an output for said composite operational amplifier which is not connected to said feedback circuits, b) a feedback resistor connected between said composite operational amplifier output and said inverting input, c) a plurality of summing inputs connected across respective summing input resistors to said inverting input to produce an inverted summed signal at said composite operational amplifier output, and d) at least one additional summing input connected across respective additional summing input resistors to said current input to produce a non-inverted summed signal which accumulates with said inverted summed signal at said composite operational amplifier output.

Claim 44

An inverting gain amplifier, comprising: a) a three-terminal operational amplifier, comprising: 1) a composite operational amplifier having inverting, non-inverting and current inputs for receiving respective externally supplied signals, said inverting and non-inverting inputs being connected as inputs in a first two-terminal operational amplifier configuration within said composite operational amplifier, and said current input together with one of said inverting and non-inverting inputs being connected as inputs to a second two-terminal operational amplifier configuration within said composite operational amplifier, said first and second two-terminal operational amplifier configurations having respective outputs, said second two-terminal operational amplifier configuration urging said current input toward a common voltage level with said inverting and non-inverting inputs, the output of said second two-terminal operational amplifier configuration being passively decoupled from said non-inverting input, 2) a first resistive feedback circuit connected between the output of one of said two-terminal operation amplifier configurations and said inverting input, 3) a second resistive feedback circuit connected between the output of said one two-terminal operational amplifier configuration and said current input, and 4) the output of the other of said two-terminal operational amplifier configurations providing an output for said composite operational amplifier which is not connected to said feedback circuits, b) a first resistor connected between said composite operational amplifier output and said inverting input, and c) a second resistor connected between said current input and a voltage reference, said inverting gain amplifier inverting and amplifying an input voltage signal at said non-inverting input in accordance with the relative resistance values of said first and second resistors.

Claim 45

An inverting gain amplifier, comprising: a) a three-terminal operational amplifier, comprising: 1) a composite operational amplifier having inverting, non-inverting and current inputs for receiving respective externally supplied signals, said inverting and non-inverting inputs being connected as inputs in a first two-terminal operational amplifier configuration within said composite operational amplifier, and said current input together with one of said inverting and non-inverting inputs being connected as inputs to a second two-terminal operational amplifier configuration within said composite operational amplifier, said first and second two-terminal operational amplifier configurations having respective outputs, said second two-terminal operational amplifier configuration urging said current input toward a common voltage level with said inverting and non-inverting inputs, the output of said second two-terminal operational amplifier configuration being passively decoupled from said non-inverting input, 2) a first resistive feedback circuit connected between the output of one of said two-terminal operation amplifier configurations and said inverting input, 3) a second resistive feedback circuit connected between the output of said one two-terminal operational amplifier configuration and said current input, and 4) the output of the other of said two-terminal operational amplifier configurations providing an output for said composite operational amplifier which is not connected to said feedback circuits, b) a first resistor connected between said composite operational amplifier output and said inverting input, and c) a second resistor connected between said current input and a voltage reference, said inverting gain amplifier inverting and amplifying an input voltage signal at said non-inverting input in accordance with the relative resistance values of said first and second resistors.

Claim 46

An instrumentation amplifier, comprising: a) a three-terminal operational amplifier, comprising: 1) a composite operational amplifier having inverting, non-inverting and current inputs, said inverting and non-inverting inputs being connected as inputs in a first two-terminal operational amplifier configuration within said composite operational amplifier, and said current input together with one of said inverting and non-inverting inputs being connected as inputs to a second two-terminal operational amplifier configuration within said composite operational amplifier, said first and second two-terminal operational amplifier configurations having respective outputs, 2) a first feedback circuit connected between the output of one of said two-terminal operational amplifier configurations and said inverting input, 3) a second feedback circuit connected between the output of said one two-terminal operational amplifier configuration and said current input, and 4) the output of the other of said two-terminal operational amplifier configurations providing an output for said composite operational amplifier which is not connected to said feedback circuits, b) a first resistor connected between said composite operational amplifier output and said inverting input, c) a second resistor connected between said current input and a voltage reference, d) a two-terminal operational amplifier having an inverting input, a non-inverting input, an output, and a feedback circuit connected between its output and its inverting input, and e) a third resistor connected between the output of said two-terminal operational amplifier and the inverting input of said three-terminal operational amplifier, said instrumentation amplifier producing an output voltage relative to said voltage reference in accordance with the values of respective input voltages applied to the non-inverting inputs of said two-terminal and three-terminal operational amplifiers and the relative resistance values of said first and third resistors.

Claim 47

An instrumentation amplifier, comprising: a) a three-terminal operational amplifier, comprising: 1) a composite operational amplifier having inverting, non-inverting and current inputs, said inverting and non-inverting inputs being connected as inputs in a first two-terminal operational amplifier configuration within said composite operational amplifier, and said current input together with one of said inverting and non-inverting inputs being connected as inputs to a second two-terminal operational amplifier configuration within said composite operational amplifier, said first and second two-terminal operational amplifier configurations having respective outputs, 2) a first feedback circuit connected between the output of one of said two-terminal operational amplifier configurations and said inverting input, 3) a second feedback circuit connected between the output of said one two-terminal operational amplifier configuration and said current input, and 4) the output of the other of said two-terminal operational amplifier configurations providing an output for said composite operational amplifier which is not connected to said feedback circuits, b) a first resistor connected between said composite operational amplifier output and said inverting input, c) a second resistor connected between said current input and a voltage reference, d) a two-terminal operational amplifier having an inverting input, a non-inverting input, an output, and a feedback circuit connected between its output and its inverting input, and e) a third resistor connected between the output of said two-terminal operational amplifier and the inverting input of said three-terminal operational amplifier, said instrumentation amplifier producing an output voltage relative to said voltage reference in accordance with the values of respective input voltages applied to the non-inverting inputs of said two-terminal and three-terminal operational amplifiers and the relative resistance values of said first and third resistors.

Claim 48

An integrator circuit, comprising: a) a three-terminal operational amplifier, comprising: 1) a composite operational amplifier having inverting, non-inverting and current inputs, said inverting and non-inverting inputs being connected as inputs in a first two-terminal operational amplifier configuration within said composite operational amplifier, and said current input together with one of said inverting and non-inverting inputs being connected as inputs to a second two-terminal operational amplifier configuration within said composite operational amplifier, said first and second two-terminal operational amplifier configurations having respective outputs, 2) a first feedback circuit connected between the output of one of said two-terminal operational amplifier configurations and said inverting input, 3) a second feedback circuit connected between the output of said one two-terminal operational amplifier configuration and said current input, and 4) the output of the other of said two-terminal operational amplifier configurations providing an output for said composite operational amplifier which is not connected to said feedback circuits, b) a first capacitor connected between said composite operational amplifier output and said inverting input, c) a first resistor connected between said inverting input and a voltage reference, and d) a second capacitor connected between said current input and said voltage reference, said integrator circuit integrating an input voltage signal at said non-inverting input in accordance with the values of said first and second capacitors and said first resistor.

Claim 49

An integrator circuit, comprising: a) a three-terminal operational amplifier, comprising: 1) a composite operational amplifier having inverting, non-inverting and current inputs, said inverting and non-inverting inputs being connected as inputs in a first two-terminal operational amplifier configuration within said composite operational amplifier, and said current input together with one of said inverting and non-inverting inputs being connected as inputs to a second two-terminal operational amplifier configuration within said composite operational amplifier, said first and second two-terminal operational amplifier configurations having respective outputs, 2) a first feedback circuit connected between the output of one of said two-terminal operational amplifier configurations and said inverting input, 3) a second feedback circuit connected between the output of said one two-terminal operational amplifier configuration and said current input, and 4) the output of the other of said two-terminal operational amplifier configurations providing an output for said composite operational amplifier which is not connected to said feedback circuits, b) a first capacitor connected between said composite operational amplifier output and said inverting input, c) a first resistor connected between said inverting input and a voltage reference, and d) a second capacitor connected between said current input and said voltage reference, said integrator circuit integrating an input voltage signal at said non-inverting input in accordance with the values of said first and second capacitors and said first resistor.

Claim 50

A differentiator circuit, comprising: a) a three-terminal operational amplifier, comprising: 1) a composite operational amplifier having inverting, non-inverting and current inputs, said inverting and non-inverting inputs being connected as inputs in a first two-terminal operational amplifier configuration within said composite operational amplifier, and said current input together with one of said inverting and non-inverting inputs being connected as inputs to a second two-terminal operational amplifier configuration within said composite operational amplifier, said first and second two-terminal operational amplifier configurations having respective outputs, 2) a first feedback circuit connected between the output of one of said two-terminal operational amplifier configurations and said inverting input, 3) a second feedback circuit connected between the output of said one two-terminal operational amplifier configuration and said current input, and 4) the output of the other of said two-terminal operational amplifier configurations providing an output for said composite operational amplifier which is not connected to said feedback circuits, b) a first resistor connected between said composite operational amplifier output and said inverting input, c) a first capacitor connected between said inverting input and a voltage reference, and d) a second resistor connected between said current input and said voltage reference, said differentiator circuit differentiating an input voltage signal at said non-inverting input in accordance with the values of said first and second resistors and said first capacitor.

Claim 51

A differentiator circuit, comprising: a) a three-terminal operational amplifier, comprising: 1) a composite operational amplifier having inverting, non-inverting and current inputs, said inverting and non-inverting inputs being connected as inputs in a first two-terminal operational amplifier configuration within said composite operational amplifier, and said current input together with one of said inverting and non-inverting inputs being connected as inputs to a second two-terminal operational amplifier configuration within said composite operational amplifier, said first and second two-terminal operational amplifier configurations having respective outputs, 2) a first feedback circuit connected between the output of one of said two-terminal operational amplifier configurations and said inverting input, 3) a second feedback circuit connected between the output of said one two-terminal operational amplifier configuration and said current input, and 4) the output of the other of said two-terminal operational amplifier configurations providing an output for said composite operational amplifier which is not connected to said feedback circuits, b) a first resistor connected between said composite operational amplifier output and said inverting input, c) a first capacitor connected between said inverting input and a voltage reference, and d) a second resistor connected between said current input and said voltage reference, said differentiator circuit differentiating an input voltage signal at said non-inverting input in accordance with the values of said first and second resistors and said first capacitor.