US4502019A
Expired / Lapsed
US
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Dynamic amplifier circuit
Assignee: US Philips Corp
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Filing: 1982-12-10
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Granted: 1985-02-26
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Expires: 2002-12-10
Abstract
Abstract A dynamic amplifier circuit, specifically for switched-capacitor filters, having a current source which supplies an exponentially-decreasing bias current. In addition, a current source is included for supplying an additional bias current in order to define the minimum bias current in the amplifier circuit.
Inventors
- 👤 Arthur H. M. Van Roermund
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:17
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/005; H03F2203/00; H03F2203/45; H03F2203/45461; H03F2203/45508
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
106 words
A dynamic amplifier circuit for amplifying a signal in a first time interval under control of a clock signal, which circuit comprises a bias circuit for obtaining a bias current in the amplifier circuit during said first time interval, which bias current decreases from an initial value, characterized in that the bias circuit comprises an additional source for obtaining a current in the amplifier circuit, which current is substantially constant relative to said bias current and has a comparatively small value relative to the said initial value in order to define the minimum bias current in the amplifier circuit at the end of said time interval.
Claim 2
Dependent Claim
106 words
A dynamic amplifier circuit for amplifying a signal in a first time interval under control of a clock signal, which circuit comprises a bias circuit for obtaining a bias current in the amplifier circuit during said first time interval, which bias current decreases from an initial value, characterized in that the bias circuit comprises an additional source for obtaining a current in the amplifier circuit, which current is substantially constant relative to said bias current and has a comparatively small value relative to the said initial value in order to define the minimum bias current in the amplifier circuit at the end of said time interval.
Claim 3
Dependent Claim
69 words
A dynamic amplifier circuit as in claim 1, in which the bias circuit comprises a switched capacitance and means for charging said capacitance during a time interval preceding the first time interval and for discharging said capacitance during the first time interval in order to obtain the variation in said bias circuit, characterized in that a current source is provided in parallel with the circuit comprising the switched capacitance.
References Cited (Backward Citations)
JPS56126303A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-02-26 | 1988-08-27 | 1989-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-26 | 1992-08-27 | 1993-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-26 | 1996-08-27 | 1997-02-26 | $7700.00 | Window Closed / Lapsed |