US5325073A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Amplifying apparatus with ac/dc feedback circuit
Assignee: Alps Alpine Co Ltd
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Filing: 1993-04-01
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Granted: 1994-06-28
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Expires: 2013-04-01
Abstract
Abstract An amplifying apparatus provided by the present invention comprises a direct-coupled inverting amplifier and an alternating-current feedback circuit as well as a direct-current feedback circuit connected between input and output terminals of the direct-coupled inverting amplifier, wherein the direct-current feedback circuit comprises an operating-point extracting circuit for extracting a direct-current component and a bias-voltage generator having a direct-current signal gain larger than an alternating-current signal gain thereof and a direct-current operating bias voltage of the direct-coupled inverting amplifier is set by using a signal output by the bias-voltage generator. Such a configuration enables the amplifying apparatus to offer high-speed operations, a large dynamic range and a highly stable direct-current operating point regardless of the type of a signal input therein and allows an alternating-current signal gain to be set independently of the stability of the direct-current operating point.
Inventors
- 👤 Kazuo Hasegawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 05:22
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/04; H03F3/08; H03F1/00; H03F1/34
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
138 words
An amplifying apparatus comprising: a direct-coupled inverting amplifier; an alternating-current feedback circuit; and a direct-current feedback circuit connected between input and output terminals of said direct-coupled inverting amplifier, wherein said direct-current feedback circuit comprises at least an operating-point extracting circuit for extracting a direct-current component and a bias-voltage generator having a direct-current signal gain larger than an alternating-current signal gain thereof and a signal output by said bias-voltage generator is used for setting a direct-current operating bias voltage of said direct-coupled inverting amplifier; and wherein said bias-voltage generator comprises a differential amplifier and a capacitive element connected between an inverting input terminal and a non-inverting input terminal of said differential amplifier, and a voltage output by said operating-point extracting circuit is supplied to said non-inverting input terminal while a reference voltage is fed to said inverting input terminal.
Claim 2
Dependent Claim
138 words
An amplifying apparatus comprising: a direct-coupled inverting amplifier; an alternating-current feedback circuit; and a direct-current feedback circuit connected between input and output terminals of said direct-coupled inverting amplifier, wherein said direct-current feedback circuit comprises at least an operating-point extracting circuit for extracting a direct-current component and a bias-voltage generator having a direct-current signal gain larger than an alternating-current signal gain thereof and a signal output by said bias-voltage generator is used for setting a direct-current operating bias voltage of said direct-coupled inverting amplifier; and wherein said bias-voltage generator comprises a differential amplifier and a capacitive element connected between an inverting input terminal and a non-inverting input terminal of said differential amplifier, and a voltage output by said operating-point extracting circuit is supplied to said non-inverting input terminal while a reference voltage is fed to said inverting input terminal.
Claim 3
Dependent Claim
18 words
An amplifying apparatus according to claim 1 characterized in that said operating-point extracting circuit comprises a low-pass filter.
Claim 4
Dependent Claim
18 words
An amplifying apparatus according to claim 1 characterized in that said operating-point extracting circuit comprises a peak holder.
Claim 5
Dependent Claim
18 words
An amplifying apparatus according to claim 1 characterized in that said operating-point extracting circuit comprises a sample holder.
Claim 6
Dependent Claim
179 words
An amplifying apparatus comprising: a direct-coupled inverting amplifier for receiving a periodical detection signal; an alternating-current feedback circuit; and a direct-current feedback circuit connected between input and output terminals of said direct-coupled inverting amplifier, wherein said alternating-current feedback circuit is designed so as to reduce a signal feedback quantity during a period wherein said detection signal is supplied and to increase said signal feedback quantity during a period wherein said detection signal is not supplied, and said direct-coupled inverting amplifier is designed so that a direct-current operating bias voltage of said direct-coupled inverting amplifier can be set by using a feedback signal output by said direct-current feedback circuit; wherein said direct-current feedback circuit comprises an operating-point extracting circuit for extracting a direct-current component and a bias-voltage generator and that a direct current operating bias voltage of said direct-coupled inverting amplifier is set by using a signal output by said bias-voltage generator; and wherein said operating-point extracting circuit employed in said direct-current feedback circuit comprises a differential amplifier having a direct-current signal gain larger than an alternating-current signal gain thereof.
Claim 7
Dependent Claim
179 words
An amplifying apparatus comprising: a direct-coupled inverting amplifier for receiving a periodical detection signal; an alternating-current feedback circuit; and a direct-current feedback circuit connected between input and output terminals of said direct-coupled inverting amplifier, wherein said alternating-current feedback circuit is designed so as to reduce a signal feedback quantity during a period wherein said detection signal is supplied and to increase said signal feedback quantity during a period wherein said detection signal is not supplied, and said direct-coupled inverting amplifier is designed so that a direct-current operating bias voltage of said direct-coupled inverting amplifier can be set by using a feedback signal output by said direct-current feedback circuit; wherein said direct-current feedback circuit comprises an operating-point extracting circuit for extracting a direct-current component and a bias-voltage generator and that a direct current operating bias voltage of said direct-coupled inverting amplifier is set by using a signal output by said bias-voltage generator; and wherein said operating-point extracting circuit employed in said direct-current feedback circuit comprises a differential amplifier having a direct-current signal gain larger than an alternating-current signal gain thereof.
Claim 8
Dependent Claim
24 words
An amplifying apparatus according to claim 5 characterized in that said operating-point extracting circuit employed in said direct-current feedback circuit comprises a low-pass filter.
Claim 9
Dependent Claim
24 words
An amplifying apparatus according to claim 5 characterized in that said operating-point extracting circuit employed in said direct-current feedback circuit comprises a peak holder.
Claim 10
Dependent Claim
27 words
An amplifying apparatus according to claim 5 characterized in that a comparator is connected to an output terminal of said direct-coupled inverting amplifier through a sample holder.
Claim 11
Dependent Claim
132 words
An amplifying apparatus comprising a direct-coupled inverting amplifier for receiving a periodical detection signal, an alternating-current feedback circuit having a switch for varying a signal-feedback quantity, a direct-current feedback circuit having a first sample holder and a second sample holder connected to an output terminal of said direct-coupled inverting amplifier, wherein said alternating-current feedback circuit and said direct-current feedback circuit are connected between input and said output terminals of said direct-coupled inverting amplifier, said amplifying apparatus characterized in that switching operations of said switch of said alternating-current feedback circuit and sampling operations of said first and second sample holders are carried out synchronously with said periodical detection signal and a direct-current operating bias voltage of said direct-coupled inverting amplifier is set by using a feedback signal output by said direct-current feedback circuit.
Claim 12
Dependent Claim
132 words
An amplifying apparatus comprising a direct-coupled inverting amplifier for receiving a periodical detection signal, an alternating-current feedback circuit having a switch for varying a signal-feedback quantity, a direct-current feedback circuit having a first sample holder and a second sample holder connected to an output terminal of said direct-coupled inverting amplifier, wherein said alternating-current feedback circuit and said direct-current feedback circuit are connected between input and said output terminals of said direct-coupled inverting amplifier, said amplifying apparatus characterized in that switching operations of said switch of said alternating-current feedback circuit and sampling operations of said first and second sample holders are carried out synchronously with said periodical detection signal and a direct-current operating bias voltage of said direct-coupled inverting amplifier is set by using a feedback signal output by said direct-current feedback circuit.
Claim 13
Dependent Claim
53 words
An amplifying apparatus according to claim 9 characterized in that said switch of said alternating-current feedback circuit is actuated so as to decrease a signal negative-feedback quantity during a period wherein said detection signal is supplied but to increase said signal negative-feedback quantity during a period wherein said detection signal is not supplied.
Claim 14
Dependent Claim
25 words
An amplifying apparatus according to claim 9 characterized in that said first sample holder performs sampling during periods wherein said detection signal is not supplied.
Claim 15
Dependent Claim
24 words
An amplifying apparatus according to claim 9 characterized in that said second sample holder performs sampling during periods wherein said detection signal is supplied.
Claim 16
Dependent Claim
23 words
An amplifying apparatus according to claim 9 characterized in that a comparator is connected to an output terminal of said second sample holder.
Claim 17
Dependent Claim
49 words
An amplifying apparatus according to claim 9 characterized in that said direct-current feedback circuit comprises an operating-point extracting circuit for extracting a direct-current component and a bias-voltage generator and that a direct-current operating bias of said direct-coupled inverting amplifier is set using a signal output by said bias-voltage generator.
Claim 18
Dependent Claim
35 words
An amplifying apparatus according to claim 10 characterized in that said bias-voltage generator employed in said direct-current feedback circuit comprises a differential amplifier having a direct-current signal gain larger than an alternating-current signal gain thereof.
Claim 19
Dependent Claim
34 words
An amplifying apparatus according to claim 9 characterized in that said direct-coupled inverting amplifier has a configuration not including an individual direct-current bias supplying means at each amplifying stage and a differential circuit portion.
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) | 1997-06-27 | 1997-12-27 | 1998-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-27 | 2001-12-27 | 2002-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-06-27 | 2005-12-27 | 2006-06-28 | $7700.00 | Window Closed / Lapsed |