Patent US4764689A successfully refreshed from Google Patents.
US4764689A
Expired / Lapsed
US
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Sample-and-hold circuit arrangement
Assignee: US Philips Corp
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Filing: 1987-05-22
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Granted: 1988-08-16
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Expires: 2007-05-22
Abstract
Abstract A sample-and-hold circuit arrangement comprising a differential amplifier (5) followed by an inverting amplifier (8). A third amplifier (12) is provided having a capacitor (14) which connects an output of the third amplifier to its input. The inverting amplifier ensures that the voltage on the output (16) of the arrangement is independent of the offset voltage of the differential amplifier (5). Moreover, during a sampling interval the capacitor (14) maintains the voltage on the output (16) at the value which it had in the directly preceding hold interval.
Inventors
- 👤 Werner F. Thommen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:13
CPC Classifications
G; G11; G11C; G11C27/00; G11C27/02; G11C27/024; G11C27/026
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
142 words
A sample-and-hold circuit comprising: an input terminal, a differential amplifier, a second amplifier of an inverting type, said second amplifier having an input terminal connected to an output terminal of said differential amplifier, means connecting the input terminal of the circuit to an input of the differential amplifier via a first switch and a first capacitor connected in series, means connecting an output of the second amplifier to said input of the differential amplifier via a second switch, a third amplifier having an input terminal connected to the output terminal of the differential amplifier via a third switch, said third amplifier having an output terminal connected, via a fourth switch, to a junction point between the first capacitor and the first switch, the input terminal and the output terminal of the third amplifier being interconnected via a branch including a second capacitor.
Claim 2
Dependent Claim
142 words
A sample-and-hold circuit comprising: an input terminal, a differential amplifier, a second amplifier of an inverting type, said second amplifier having an input terminal connected to an output terminal of said differential amplifier, means connecting the input terminal of the circuit to an input of the differential amplifier via a first switch and a first capacitor connected in series, means connecting an output of the second amplifier to said input of the differential amplifier via a second switch, a third amplifier having an input terminal connected to the output terminal of the differential amplifier via a third switch, said third amplifier having an output terminal connected, via a fourth switch, to a junction point between the first capacitor and the first switch, the input terminal and the output terminal of the third amplifier being interconnected via a branch including a second capacitor.
Claim 3
Dependent Claim
25 words
A sample-and-hold circuit as claimed in claim 1, characterized in that the second amplifier and the third amplifier have transfer characteristics that are substantially identical.
Claim 4
Dependent Claim
41 words
A sample-and-hold circuit as claimed in claim 1 further comprising a fifth switch which connects said input terminal of the second amplifier to said output terminal of the differential amplifier, said third and fifth switches being closed in alternate time intervals.
Claim 5
Dependent Claim
50 words
A sample-and-hold circuit as claimed in claim 3 wherein, during a sampling interval, said first, second and fifth switches are closed and the third and fourth switches are open, and during a hold interval, the third and fourth switches are closed and the first, second and fifth switches are open.
Claim 6
Dependent Claim
23 words
A sample-and-hold circuit as claimed in claim 4 wherein the differential amplifier comprises a second input connected to a source of reference voltage.
Claim 7
Dependent Claim
29 words
A sample-and-hold circuit as claimed in claim 1 further comprising a third capacitor coupled between said output of the second amplifier and the input terminal of the second amplifier.
Claim 8
Dependent Claim
37 words
A sample-and-hold circuit as claimed in claim 3 further comprising a third capacitor coupled between said output of the second amplifier and a junction point between the fifth switch and said input terminal of the second amplifier
Claim 9
Dependent Claim
156 words
A sample-and-hold circuit comprising: an input terminal, a differential amplifier, a second amplifier of an inverting type, said second amplifier having an input terminal connected to an output terminal of said differential amplifier, means connecting the input terminal of the circuit to an input of the differential amplifier via a first switch and a first capacitor connected in series, said differential amplifier having a second input connected to a source of reference voltage, means connecting an output of the second amplifier to an input of the differential amplifier via a second switch, a third amplifier having an input terminal connected to the output terminal of the differential amplifier via a third switch, said third amplifier having an output terminal connected, via a fourth switch, to a junction point between the first capacitor and the first switch, the input terminal and the output terminal of the third amplifier being interconnected via a branch including a second capacitor.
Claim 10
Dependent Claim
156 words
A sample-and-hold circuit comprising: an input terminal, a differential amplifier, a second amplifier of an inverting type, said second amplifier having an input terminal connected to an output terminal of said differential amplifier, means connecting the input terminal of the circuit to an input of the differential amplifier via a first switch and a first capacitor connected in series, said differential amplifier having a second input connected to a source of reference voltage, means connecting an output of the second amplifier to an input of the differential amplifier via a second switch, a third amplifier having an input terminal connected to the output terminal of the differential amplifier via a third switch, said third amplifier having an output terminal connected, via a fourth switch, to a junction point between the first capacitor and the first switch, the input terminal and the output terminal of the third amplifier being interconnected via a branch including a second capacitor.
Claim 11
Dependent Claim
42 words
A sample-and-hold circuit as claimed in claim 8 further comprising a fifth switch which connects said input terminal of the second amplifier to said output terminal of the differential amplifier, said third and fifth switches being closed in mutually exclusive time intervals.
Claim 12
Dependent Claim
40 words
A sample-and-hold circuit as claimed in claim 9 wherein said second and third amplifiers have substantially identical transfer characteristics, whereby a voltage at the output terminal of the third amplifier is independent of any offset voltage of the differential amplifier.
Claim 13
Dependent Claim
23 words
A sample-and-hold circuit as claimed in claim 1 further comprising a circuit output terminal coupled to the output terminal of the third amplifier.
Claim 14
Dependent Claim
31 words
A sample-and-hold circuit as claimed in claim 9 wherein said fifth switch is closed and said third switch is open during a sampling interval, and vice versa during a hold interval.
Claim 15
Dependent Claim
29 words
A sample-and-hold circuit as claimed in claim 12 further comprising a third capacitor coupled between said output of the second amplifier and the input terminal of the second 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) | 1991-08-16 | 1992-02-15 | 1992-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-16 | 1996-02-15 | 1996-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-16 | 2000-02-15 | 2000-08-16 | $7700.00 | Window Closed / Lapsed |