US5929664A
Expired / Lapsed
US
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Methods, circuits and devices for improving crossover performance and/or monotonicity, and applications of the same in a universal serial bus (USB) low speed output driver
Assignee: Monterey Research LLC
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Filing: 1997-09-22
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Granted: 1999-07-27
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Expires: 2017-09-22
Abstract
Abstract A circuit comprising a first driver circuit, a second driver circuit and a delay circuit. The first driver circuit may be configured to generate a first output signal and a control signal in response to a first input signal. The delay circuit may be configured to generate a delay signal in response to a second input signal and the control signal. The second driver circuit may be configured to generate a second output signal in response to the delay signal.
Inventors
- 👤 Gary W. Alleven
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:32
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/16; H03K17/161; H03K17/162
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
131 words
A circuit comprising: a comparator circuit configured to present an output signal in response to (i) a reference voltage and (ii) a control signal comprising a fixed portion and a variable portion; a control circuit configured to generate said control signal in response to (i) a first current source configured to present said fixed portion of the current of said control signal, (ii) a second current source configured to present said variable portion of the current of said control signal and (iii) said output signal of said comparator circuit, said second current source configured to respond to a level of said output signal; and a driver circuit configured to generate a driver output signal, wherein a crossover point of said driver output signal is adjusted in response to said control signal.
Claim 2
Dependent Claim
131 words
A circuit comprising: a comparator circuit configured to present an output signal in response to (i) a reference voltage and (ii) a control signal comprising a fixed portion and a variable portion; a control circuit configured to generate said control signal in response to (i) a first current source configured to present said fixed portion of the current of said control signal, (ii) a second current source configured to present said variable portion of the current of said control signal and (iii) said output signal of said comparator circuit, said second current source configured to respond to a level of said output signal; and a driver circuit configured to generate a driver output signal, wherein a crossover point of said driver output signal is adjusted in response to said control signal.
Claim 3
Dependent Claim
36 words
The circuit according to claim 1, wherein said fixed portion of the current of the control signal comprises a static current and said variable portion of the current of the control signal comprises a dynamic current.
Claim 4
Dependent Claim
29 words
The circuit according to claim 1, wherein said second current source is controlled by a transistor of said control circuit having a threshold voltage corresponding to said reference voltage.
Claim 5
Dependent Claim
25 words
The circuit according to claim 1, wherein said driver circuit is at least part of an output driver circuit of a Universal Serial Bus device.
Claim 6
Dependent Claim
26 words
The circuit according to claim 1, wherein said control circuit comprises a transistor configured to disable said first current source in response to an enable signal.
Claim 7
Dependent Claim
19 words
The circuit according to claim 1, wherein said reference voltage is generated in response to a third current source.
Claim 8
Dependent Claim
15 words
The circuit according to claim 1, wherein said control signal provides compensation for process variations.
Claim 9
Dependent Claim
100 words
A circuit comprising: means for generating an output signal in response to (i) a reference voltage and (ii) a control signal; means for generating a static current portion of said control signal in response to a first current source and an enable signal; means for generating a dynamic current portion of said control signal, coupled to said means for generating said static current portion, in response to said output signal and a second current source; and means for generating a driver output signal, wherein a crossover point of said driver output signal is adjusted in response to said control signal.
Claim 10
Dependent Claim
100 words
A circuit comprising: means for generating an output signal in response to (i) a reference voltage and (ii) a control signal; means for generating a static current portion of said control signal in response to a first current source and an enable signal; means for generating a dynamic current portion of said control signal, coupled to said means for generating said static current portion, in response to said output signal and a second current source; and means for generating a driver output signal, wherein a crossover point of said driver output signal is adjusted in response to said control signal.
Claim 11
Dependent Claim
34 words
The circuit according to claim 8, wherein said second current source is controlled by a transistor of said means for generating said dynamic current portion having a threshold voltage corresponding to said reference voltage.
Claim 12
Dependent Claim
28 words
The circuit according to claim 8, wherein said means for generating said driver output signal comprises a transistor of an output driver circuit of a Universal Serial Bus.
Claim 13
Independent Claim
113 words
A method for compensating for propagation and process variations in an output driver comprising the steps of: comparing (i) a reference voltage and (ii) a control signal comprising a fixed current portion and a variable current portion to generate an output signal; generating a first current representing said fixed current portion of said control signal in response to an enable signal and a first current source; generating a second current representing said variable current portion of said control signal in response to said output signal and a second current source; and generating a driver output signal, wherein a crossover point of said driver output signal is adjusted in response to said control signal.
Claim 14
Independent Claim
113 words
A method for compensating for propagation and process variations in an output driver comprising the steps of: comparing (i) a reference voltage and (ii) a control signal comprising a fixed current portion and a variable current portion to generate an output signal; generating a first current representing said fixed current portion of said control signal in response to an enable signal and a first current source; generating a second current representing said variable current portion of said control signal in response to said output signal and a second current source; and generating a driver output signal, wherein a crossover point of said driver output signal is adjusted in response to said control signal.
Claim 15
Dependent Claim
24 words
The method according to claim 11, further comprising the step of: disabling the generation of said second current in response to said enable signal.
Claim 16
Dependent Claim
21 words
The method according to claim 11, further comprising the step of: generating said reference voltage in response to a third current.
Claim 17
Dependent Claim
26 words
The method according to claim 11, wherein said fixed current portion comprises a static current portion and said variable current portion comprises a dynamic current portion.
Claim 18
Dependent Claim
35 words
The method according to claim 11, wherein the step of generating said driver output signal comprises: controlling a transistor of said output driver, wherein said output driver is included in a Universal Serial Bus device.
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) | 2002-07-26 | 2003-01-25 | 2003-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-07-26 | 2007-01-25 | 2007-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-07-26 | 2011-01-25 | 2011-07-27 | $7700.00 | Window Closed / Lapsed |