US RE38455 E1 Abstract Integrated circuitry for selectively introducing capacitance and for controlling the transconductance transfer function of one or more amplifiers includes concatenated differential amplifiers with one or more pairs of switchable capacitive components differentially connected across outputs of the differential amplifiers to facilitate operation over a wide range of operating frequencies under control of external signals.
Claims(27) 1. Integrator apparatus comprising:
an amplifier including a pair of outputs and being responsive to differential input signals for producing differential output signals on the pair of outputs; and
a pair of capacitive components connected to the pair of outputs and to a common source of first control signal, the capacitive components including insulated-gate, field-effect transistors having gates connected to respective ones of the pair of outputs and having sources and drains connected in common to receive said first control signal for altering the capacitance of each pair of capacitive component in response to the first control signal applied to the sources and drains thereof.
2. Integrator apparatus according to
3. Integrator apparatus according to
4. Integrator apparatus according to
a current source connected to the drain electrode of each transistor, and another current source connected to the common connection of the source electrodes for conducting the sum of currents in the conduction channels of the pair of transistors.
5. Integrator apparatus according to
6. Integrator apparatus according to
7. Integrator apparatus comprising:
a plurality of differential amplifiers connected in parallel,
said plurality of differential amplifiers having differential inputs connected in common to receive an applied differential signal,
said plurality of differential amplifiers having differential outputs connected in common to output a differential amplified signal, and
each of said plurality of differential amplifiers having a transfer function from input thereof to output thereof, wherein each of said plurality of differential amplifiers is individually controllable in response to a respective control signal applied thereto, for altering the transfer function of a corresponding one of said plurality of differential amplifiers from the input thereof to the output thereof.
8. Integrator apparatus, comprising:
a plurality of differential amplifiers connected in parallel,
said plurality of differential amplifiers having differential outputs connected in common to output a differential amplified signal,
each of said plurality of differential amplifiers having a transfer function from input thereof to output thereof, wherein each of said plurality of differential amplifiers is individually controllable in response to a respective control signal applied thereto, for altering the transfer function of a corresponding one of said plurality of differential amplifiers from the input thereof to the output thereof, and
wherein each of said plurality of differential amplifiers is selectively enabled or disabled.
9. Integrator apparatus, comprising:
a plurality of differential amplifiers connected in parallel,
wherein each of said plurality of differential amplifiers is selectively controllable to expand the linear range of a combined transfer function of the integrator apparatus.
10. Integrator apparatus according to
11. An amplifier comprising:
a plurality of differential amplifiers, each having:
a pair of gain elements having (i) a pair of differential input terminals, (ii) a pair of differential output terminals, and (iii) a pair of common terminals; and a controllable current source in combination with said pair of common terminals,
wherein said plurality of differential amplifiers are connected in parallel,
wherein each of said pair of differential input terminals is connected in common with the differential input terminals of other ones of said plurality of differential amplifiers,
wherein each of said pair of differential output terminals is connected in common with the differential output terminals of other ones of said plurality of differential amplifiers,
wherein each of said plurality of differential amplifiers has a response characteristic defined by a corresponding transfer function from said pair of input terminals to said pair of output terminals, and
wherein each of said controllable current source individually controls the corresponding transfer function of a respective one of said plurality of differential amplifiers.
12. An amplifier, comprising:
a plurality of differential amplifiers, each having:
a pair of gain elements having:
(
i) a pair of differential input terminals, (
ii) a pair of differential output terminals, and (
iii) a pair of common terminals; and a controllable current source in combination with said pair of common terminals,
wherein said plurality of differential amplifiers are connected in parallel,
wherein each of said plurality of differential amplifiers has a response characteristic defined by a corresponding transfer function from said pair of input terminals to said pair of output terminals,
wherein each of said controllable current source individually controls the corresponding transfer function of a respective one of said plurality of differential amplifiers, and
wherein each of said plurality of differential amplifiers is selectively enabled or disabled.
13. An amplifier, comprising:
a plurality of differential amplifiers, each having:
a pair of gain elements having:
(
i) a pair of differential input terminals, (
ii) a pair of differential output terminals, and (
iii) a pair of common terminals; and a controllable current source in communication with said pair of common terminals,
wherein said plurality of differential amplifiers are connected in parallel,
wherein each of said plurality of differential amplifiers is selectively controllable to expand the linear range of a combined transfer function of the amplifier.
14. An amplifier comprising:
a plurality of differential amplifiers connected in parallel, each having:
a pair of differential input terminals;
a pair of differential output terminals; and
a controllable current source,
15. An amplifier, comprising:
a plurality of differential amplifiers connected in parallel, each having:
a pair of differential input terminals;
a pair of differential output terminals; and
a controllable current source,
wherein each of said plurality of differential amplifiers is selectively enabled or disabled.
16. An amplifier, comprising:
a plurality of differential amplifiers connected in parallel, each having:
a pair of differential input terminals,;
a pair of differential output terminals; and
a controllable current source,
17. Integrator apparatus comprising:
a plurality of differential amplifier means for amplifying a differential signal connected in parallel,
said plurality of differential amplifier means having differential inputs connected in common to receive an applied differential signal,
said plurality of differential amplifier means having differential outputs connected in common to output a differential amplified signal, and
each of said plurality of differential amplifier means having a transfer function from input thereof to output thereof, wherein each of said plurality of differential amplifier means is individually controllable in response to a respective control signal applied thereto, for altering the transfer function of a corresponding one of said plurality of differential amplifier means from the input thereof to the output thereof.
18. Integrator apparatus, comprising:
said plurality of differential amplifier means having differential outputs connected in common to output a differential amplified signal,
each of said plurality of differential amplifier means having a transfer function from input thereof to output thereof, wherein each of said plurality of differential amplifier means is individually controllable in response to a respective control signal applied thereto, for altering the transfer function of a corresponding one of said plurality of differential amplifier means from the input thereof to the output thereof, and
wherein each of said plurality of differential amplifier means is selectively enabled or disabled.
19. Integrator apparatus, comprising:
wherein each of said plurality of differential amplifier means is selectively controllable to expand the linear range of a combined transfer function of the integrator apparatus.
20. An amplifier comprising:
a plurality of differential amplifier means for amplifying a differential signal, each having:
a pair of gain means having (i) a pair of differential input means for inputting a differential signal, (ii) a pair of differential output means for outputting a differential signal, and (iii) a pair of common means; and a controllable current source means for providing a current in communication with said pair of common means;
wherein said plurality of differential amplifier means are connected in parallel;
wherein each of said pair of differential input means is connected in common with the differential input means of other ones of said plurality of differential amplifier means;
wherein each of said pair of differential output means is connected in common with the differential output means of other ones of said plurality of differential amplifier means;
wherein each of said plurality of differential amplifier means has a response characteristic defined by a corresponding transfer function from said pair of input means to said pair of output means; and
wherein each of said controllable current source means individually controls the corresponding transfer function of a respective one of said plurality of differential amplifier means.
21. An amplifier, comprising:
a plurality of differential amplifier means for amplifying a differential signal, each having:
a pair of gain means having:
(
i) a pair of differential input means for inputting a differential signal, (
ii) a pair of differential output means for outputting a differential signal, and (
iii) a pair of common means; and wherein said plurality of differential amplifier means are connected in parallel;
wherein each of said plurality of differential amplifier means has a response characteristic defined by a corresponding transfer function from said pair of input means to said pair of output means,
wherein each of said controllable current source means individually controls the corresponding transfer function of a respective one of said plurality of differential amplifier means, and
wherein each of said plurality of differential amplifier means is selectively enabled or disabled.
22. An amplifier, comprising:
a plurality of differential amplifier means for amplifying a differential signal, each having:
a pair of gain means having:
(
i) a pair of differential input means for inputting a differential signal, (
ii) a pair of differential output means for outputting a differential signal, and (
iii) a pair of common means; and a controllable current source means for providing a current in communication with said pair of common means,
wherein said plurality of differential amplifier means are connected in parallel,
wherein each of said pair of differential input means is connected in common with the differential input means of other ones of said plurality of differential amplifier means,
wherein each of said pair of differential output means is connected in common with the differential output means of other ones of said plurality of differential amplifier means,
wherein each of said plurality of differential amplifier means is selectively controllable to expand the linear range of a combined transfer function of the amplifier.
23. An amplifier comprising:
a plurality of differential amplifier means connected in parallel, each having:
a pair of differential input means for inputting a differential signal,
a pair of differential output means for outputting a differential signal, and
a controllable current source means for supplying a current;
24. An amplifier, comprising:
a plurality of differential amplifier means connected in parallel, each having:
a pair of differential input means for inputting a differential signal,
a pair of differential output means for outputting a differential signal, and
a controllable current source means for supplying a current;
wherein each of said plurality of differential amplifier means is selectively enabled or disabled.
25. An amplifier, comprising:
a plurality of differential amplifier means connected in parallel, each having:
a pair of differential input means for inputting a differential signal,
a pair of differential output means for outputting a differential signal, and
a controllable current source means for supplying a current;
26. A method of integrating an applied differential signal comprising the steps of:
providing a plurality of differential amplifiers connected in parallel,
arranging differential inputs of the plurality of differential in common to receive the applied differential signal,
arranging differential outputs of the plurality of differential amplifiers in common to output a differential amplified signal,
wherein each of the plurality of differential amplifiers has a transfer function from input thereof to output thereof, and
individually controlling each of said plurality of differential amplifiers in response to a respective control signal applied thereto, for altering the transfer function of a corresponding one of said plurality of differential amplifiers from the input thereof to the output thereof.
27. A method of amplifier an applied signal comprising the steps of:
providing a plurality of differential amplifiers, each having:
a pair of gain elements having (i) a pair of differential input terminals, (ii) a pair of differential output terminals, and (iii) a pair of common terminals; applying a current to the pair of common terminals;
arranging the plurality of differential amplifiers in parallel;
arranging each of the pair of differential input terminals in common with the differential input terminals of other ones of the plurality of differential amplifiers;
arranging each of the pair of differential output terminals in common with the differential output terminals of other ones of the plurality of differential amplifiers;
wherein each of the plurality of differential amplifiers has a response characteristic defined by a corresponding transfer function from the pair of input terminals to the pair of output terminals; and
individually controlling the current applied to a respective one of the plurality of differential amplifiers to individually control the corresponding transfer function thereof.
Description Notice: More than one reissue application has been filed for the reissue of U.S. Pat. No. and (09/950,086 the present application), which is a continuation reissue application of U.S. Pat. No. 5,805,006.This invention relates to integrators and more particularly to circuitry in an integrated circuit that controls frequency response characteristics over a wide range of frequencies with adjustable capacitance and controllable transconductance. Circuit components formed in integrated circuits commonly exhibit wide variations in operating characteristics attributable to variations in the semiconductor processes that form the integrated circuit of such components. By traditional design practices, additional or redundant components may be formed in an integrated circuit during the processing phase, and such additional components may thereafter be connected in or out of a circuit using a laser beam to selectively sever connecting links as required to adjust the operating characteristics of the circuit. Alternatively, signal controllable switches may be incorporated into the design of the integrated circuit to selectively connect additional components in response to externally applied control signals. However, such switches are not ideal in that they incorporate appreciable resistance into a circuit in the conductive state which can be detrimental to high frequency operating characteristics of the integrated circuit. In accordance with one embodiment of the present invention, additional capacitive components may be selectively switched into circuit configuration in response to external control signals without introducing significant resistance with the capacitive components. In addition, controllable gain elements may be selectively controlled to amplify the effectiveness of capacitive components in the circuit for a wide range of operating frequency characteristics of the circuit as selectively configured. FIG. 1 is a circuit diagram of a conventional transconductance integrator; FIG. 2 is a circuit diagram of one embodiment of the present invention; FIG. 3 is a graph illustrating the operating characteristics of a transconductance amplifier; and FIG. 4 is a circuit diagram of another embodiment of the present invention for providing wide dynamic control of operating frequency characteristics of the composite circuitry. Referring now to FIG. 1, there is shown a conventional integrator including a differential pair of gain stages In accordance with one embodiment of the present invention, one or more differential pairs of capacitive elements are formed for selective connection into the circuit in response to an applied control signal. Specifically, as shown in FIG. 2, each capacitive element is formed as a pair of gain elements Referring now to FIG. 3, there is shown a graph of the transfer function of the differential amplifier of FIG. 2 that includes gain elements In accordance with another embodiment of the present invention, a plurality of amplifiers similar to the amplifier of FIG. 2 are assembled in parallel, as illustrated in FIG. 4, between the differential inputs Therefore, one design of integrated circuit according to the present invention facilitates formation of g Patent Citations
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