Patent US5877654A successfully refreshed from Google Patents.
US5877654A
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Class a amplifier with a digitally programmable miller compensation network
Assignee: NXP USA Inc
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Filing: 1996-12-02
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Granted: 1999-03-02
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Expires: 2016-12-02
Abstract
Abstract A class A driver circuit (30) has an output stage with a plurality of selectable current sources (42). The selectable current sources (42) are used to optimize the drive capability of the output stage of the class A driver circuit (30) for different applications having different output impedance. In one embodiment, the selectable current sources (42) may be selectable, or switchable, using software programmed by a user. In another embodiment, the current sources may be automatically selected, based on sensing the output current provided to a resistive load. Also, in yet another embodiment, the selectable current sources (42) may be selectable based on the input signal of a first stage amplifier (32). A Miller compensation network (40) includes digitally controlled, switchable capacitors (129) and resistors (128), and provides the necessary amount of Miller compensation for the selected current sources.
Inventors
- 👤 Joseph Yves Chan Yan Fong
- 👤 Mathew A. Rybicki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 12:26
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/08; H03F1/083; H03F1/086
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
131 words
An amplifier comprising: a first stage amplifier having an output; a second stage amplifier having an input and an output, wherein the input is connected to the output of the first stage; and a digitally programmable Miller network having a plurality of switchable capacitive elements connected between the output of the first stage amplifier and the output of the second stage amplifier, wherein each capacitive element of the plurality of switchable capacitive elements has a node connected to a first node of a corresponding transistor and, wherein a second node of each corresponding transistor is connected to a node of another of the plurality of capacitive elements, wherein one or more of the corresponding transistors are activated to connect two or more of the plurality of switchable capacitive elements in parallel.
Claim 2
Dependent Claim
131 words
An amplifier comprising: a first stage amplifier having an output; a second stage amplifier having an input and an output, wherein the input is connected to the output of the first stage; and a digitally programmable Miller network having a plurality of switchable capacitive elements connected between the output of the first stage amplifier and the output of the second stage amplifier, wherein each capacitive element of the plurality of switchable capacitive elements has a node connected to a first node of a corresponding transistor and, wherein a second node of each corresponding transistor is connected to a node of another of the plurality of capacitive elements, wherein one or more of the corresponding transistors are activated to connect two or more of the plurality of switchable capacitive elements in parallel.
Claim 3
Dependent Claim
27 words
An amplifier according to claim 1, wherein the first stage is a differential operational amplifier and the second stage has an amplifying device and a current source.
Claim 4
Dependent Claim
15 words
An amplifier according to claim 1, wherein the digitally programmable Miller network is automatically programmable.
Claim 5
Dependent Claim
27 words
An amplifier according to claim 1, further comprising a resistive element connected in series between the output of the first stage and the plurality of capacitive elements.
Claim 6
Dependent Claim
15 words
An amplifier according to claim 4, wherein the resistive element is a digitally controlled transistor.
Claim 7
Dependent Claim
91 words
An amplifier comprising: a first stage amplifier having an input and an output; a second stage amplifier having a first input, a first output, and a first set of switchable current sources electrically coupled in parallel to the first stage amplifier output, wherein the first input of the second stage is connected to the output of the first stage amplifier; and a digitally programmable Miller network having a plurality of switchable capacitive elements connected between the output of the first stage amplifier and the first output of the second stage amplifier.
Claim 8
Dependent Claim
91 words
An amplifier comprising: a first stage amplifier having an input and an output; a second stage amplifier having a first input, a first output, and a first set of switchable current sources electrically coupled in parallel to the first stage amplifier output, wherein the first input of the second stage is connected to the output of the first stage amplifier; and a digitally programmable Miller network having a plurality of switchable capacitive elements connected between the output of the first stage amplifier and the first output of the second stage amplifier.
Claim 9
Dependent Claim
49 words
An amplifier according to claim 6, further comprising a logic circuit that receives program signals from a register and switches one or more of the first set of switchable current sources and switches one or more of the plurality of switchable capacitive elements in response to the program signals.
Claim 10
Dependent Claim
20 words
An amplifier according to claim 6, wherein the digitally programmable Miller network further comprises a plurality of selectable resistive elements.
Claim 11
Dependent Claim
39 words
An amplifier according to claim 6, wherein the first set of switchable current sources includes a current source transistor in series with a first switchable cascode transistor and a second switchable cascode transistor in series with an amplifying transistor.
Claim 12
Dependent Claim
105 words
An amplifier according to claim 6, wherein the input to the first stage is a differential input and the output of the first stage is a differential output having a first polarity signal and a second polarity signal, and further wherein the second stage amplifier further comprises a second input and a second output, wherein the first input of the second stage is connected to the first polarity signal and the second input of the second stage is connected to the second polarity signal, and further comprising a second set of current sources connected in parallel to the second output of the second stage amplifier.
Claim 13
Dependent Claim
70 words
An amplifier according to claim 10, further comprising a common mode regulation circuit having a first input, a second input and an output, wherein the first input is connected to the first output and the second output of the second stage amplifier, the second input is connected to a reference voltage and the output provides a control signal to the first stage amplifier that regulates the output of the amplifier.
Claim 14
Dependent Claim
51 words
An amplifier according to claim 6, further comprising an automatic control circuit that receives one or more program signals and switches one or more of the first set of switchable current sources and one or more of the switchable capacitive elements as a function of the one or more program signals.
Claim 15
Dependent Claim
104 words
An amplifier according to claim 12, wherein the automatic control circuit further comprises: one or more sense transistors connected in parallel to a current summing node, wherein the one or more sense transistors are controlled by at least the first output of the first stage; a current mirror having an output and an input, the current summing node being connected to the input of the current mirror; and an analog-to-digital converter having an analog input and a digital output, the output of the current mirror being connected to the input of the analog-to-digital converter and the analog-to-digital converter outputting one or more program signals.
Claim 16
Dependent Claim
50 words
An amplifier according to claim 12, wherein the automatic control circuit receives the input to the first stage amplifier, and further wherein the automatic control determines an amplitude of the input to the first stage amplifier, and outputs the one or more program signals as a function of the amplitude.
Claim 17
Dependent Claim
27 words
An amplifier according to claim 6, wherein the first stage is a differential operational amplifier and the second stage has an amplifying device and a current source.
Claim 18
Dependent Claim
15 words
An amplifier according to claim 6, wherein the digitally programmable Miller network is automatically programmable.
Claim 19
Dependent Claim
74 words
An amplifier according to claim 6, wherein each capacitive element of the plurality of switchable capacitive elements has a node connected to a first node of a corresponding transistor and wherein a second node of each corresponding transistor is connected to a node of another of the plurality of capacitive elements, wherein one or more of the corresponding transistors are activated to connect two or more of the plurality of capacitive elements in parallel.
Claim 20
Dependent Claim
28 words
An amplifier according to claim 6, further comprising a resistive element connected in series between the output of the first stage and the plurality of switchable capacitive elements.
Claim 21
Dependent Claim
17 words
An amplifier according to claim 18, wherein the resistive element is one or more digitally controlled transistor.
Claim 22
Dependent Claim
130 words
An amplifier comprising: a first stage amplifier having an input and an output; a second stage amplifier having a first input, a first output, and a first set of switchable current sources electrically coupled in parallel to the output, wherein the first input of the second stage is connected to the output of the first stage; a digitally programmable Miller network having a plurality of switchable capacitive elements connected between the output of the first stage amplifier and the first output of this second stage amplifier; and an automatic control circuit that receives one or more program signals and switches one or more of the first set of switchable current sources and one or more of the switchable capacitive elements as a function of the one or more program signals.
Claim 23
Dependent Claim
130 words
An amplifier comprising: a first stage amplifier having an input and an output; a second stage amplifier having a first input, a first output, and a first set of switchable current sources electrically coupled in parallel to the output, wherein the first input of the second stage is connected to the output of the first stage; a digitally programmable Miller network having a plurality of switchable capacitive elements connected between the output of the first stage amplifier and the first output of this second stage amplifier; and an automatic control circuit that receives one or more program signals and switches one or more of the first set of switchable current sources and one or more of the switchable capacitive elements as a function of the one or more program signals.
Claim 24
Dependent Claim
104 words
An amplifier according to claim 20, wherein the automatic control circuit further comprises: one or more sense transistors connected in parallel to a current summing node, wherein the one or more sense transistors are controlled by at least the first output of the first stage; a current mirror having an output and an input, the current summing node being connected to the input of the current mirror; and an analog-to-digital converter having an analog input and a digital output, the output of the current mirror being connected to the input of the analog-to-digital converter and the analog-to-digital converter outputting one or more program signals.
Claim 25
Dependent Claim
50 words
An amplifier according to claim 20, wherein the automatic control circuit receives the input to the first stage amplifier, and further wherein the automatic control determines an amplitude of the input to the first stage amplifier, and outputs the one or more program signals as a function of the amplitude.
Claim 26
Dependent Claim
27 words
An amplifier according to claim 20, wherein the first stage is a differential operational amplifier and the second stage has an amplifying device and a current source.
Claim 27
Dependent Claim
75 words
An amplifier according to claim 20, wherein each capacitive element of the plurality of switchable capacitive elements has a node connected to a first node of a corresponding transistor and, wherein a second node of each corresponding transistor is connected to a node of another of the plurality of capacitive elements, wherein one or more of the corresponding transistors are activated to connect two or more of the plurality of switchable capacitive elements in parallel.
Claim 28
Dependent Claim
15 words
An amplifier according to claim 20, wherein the digitally programmable Miller network is automatically programmable.
Claim 29
Dependent Claim
27 words
An amplifier according to claim 20, further comprising a resistive element connected in series between the output of the first stage and the plurality of capacitive elements.
Claim 30
Dependent Claim
21 words
An amplifier according to claim 20, wherein the digitally programmable Miller network further comprises a plurality of switchable selectable resistive elements.
Claim 31
Dependent Claim
17 words
An amplifier according to claim 27, wherein the plurality of selectable resistive elements are digitally controlled transistors.
Claim 32
Dependent Claim
39 words
An amplifier according to claim 20, wherein the first set of switchable current sources includes a current source transistor in series with a first switchable cascode transistor and a second switchable cascode transistor in series with an amplifying transistor.
Claim 33
Dependent Claim
104 words
An amplifier according to claim 20, wherein the input to the first stage is a differential input and the output of the first stage is a differential output having a first polarity signal and second polarity signal, and further wherein the second stage amplifier further comprises a second input and a second output, wherein the first input of the second stage is connected to the first polarity signal and the second input of the second stage is connected to the second polarity signal, and further comprising a second set of current sources connected in parallel to the second output of the second stage amplifier.
Claim 34
Dependent Claim
69 words
An amplifier according to claim 30, further comprising a common mode regulation circuit having a first input, a second input and an output, wherein the first inputs connected to the first output and the second output of the second stage amplifier, the second input is connected to a reference voltage and the output provides a control signal to the first stage amplifier that regulates the output of the amplifier.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-03-01 | 2002-08-31 | 2003-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-03-01 | 2006-08-31 | 2007-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-03-01 | 2010-08-31 | 2011-03-02 | $7700.00 | Window Closed / Lapsed |