US4163948A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filter for digital-to-analog converter
Assignee: Tektronix Inc
•
Filing: 1978-04-27
•
Granted: 1979-08-07
•
Expires: 1998-04-27
Abstract
Abstract A circuit for attenuating undesired electrical aberrations associated with digital-to-analog converters is provided. Specifically, the circuit is a non-linear filter for attenuating undesired false or spurious electronic signals superimposed on the output waveform of a digital-to-analog converter when the digital word input signal is changed.
Inventors
- 👤 Michael L. Rieger
- 👤 Martin D. Singer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:55
CPC Classifications
H; H03; H03K; H03K5/00; H03K5/01; H03H; H03H11/00; H03H11/02; H03H11/04; H03H11/0405; H03H11/12; H03H11/1213; H03H11/1217; H03K4/00; H03K4/02; H03K5/125; H03K5/1252; H03M; H03M1/00; H03M1/06; H03M1/0617; H03M1/0626; H03M1/0629; H03M1/08; H03M1/0863; H03M1/0872
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
174 words
A non-linear filter for attenuating spurious electronic signals, the filter comprising: circuit input means for receiving the signals to be attenuated; first amplifier means coupled to said circuit input means for amplifying the signals to be attenuated and including means for providing the amplified signals as double-ended signals; second amplifier means coupled to receive said double-ended signals for providing a single ended output signal, said second amplifier means including constant current source means for providing a constant current; current mirror means coupled to receive said single-ended output signal for sinking said constant current; a capacitor coupled to receive at least a portion of said constant current for producing a terminal voltage thereacross in accordance with said constant current received; buffer amplifier means responsive to said terminal voltage for applying said terminal voltage to a circuit output means; and feedback means coupled between said circuit input means and said circuit output means for feeding at least a portion of said terminal voltage to said first amplifier means for controlling the amplitude of said terminal voltage.
Claim 2
Dependent Claim
174 words
A non-linear filter for attenuating spurious electronic signals, the filter comprising: circuit input means for receiving the signals to be attenuated; first amplifier means coupled to said circuit input means for amplifying the signals to be attenuated and including means for providing the amplified signals as double-ended signals; second amplifier means coupled to receive said double-ended signals for providing a single ended output signal, said second amplifier means including constant current source means for providing a constant current; current mirror means coupled to receive said single-ended output signal for sinking said constant current; a capacitor coupled to receive at least a portion of said constant current for producing a terminal voltage thereacross in accordance with said constant current received; buffer amplifier means responsive to said terminal voltage for applying said terminal voltage to a circuit output means; and feedback means coupled between said circuit input means and said circuit output means for feeding at least a portion of said terminal voltage to said first amplifier means for controlling the amplitude of said terminal voltage.
Claim 3
Dependent Claim
22 words
The filter according to claim 1 further comprising additional circuit means for providing an additional constant current for said second amplifier means.
Claim 4
Dependent Claim
148 words
A non-linear filter for attenuating spurious electronic signals, the filter comprising: means for receiving the signal to be attenuated; a first amplifier coupled to said signal receiving means for amplifying the signals to be attenuated and including means for providing the amplified signals as double-ended signals; a second amplifier coupled to said first amplifier and to receive said double-ended signals for providing a single-ended output signal, said second amplifier including a constant current source for providing a constant current; storage means coupled to said second amplifier and to receive at least a portion of said constant current for producing a terminal voltage thereacross in accordance with said constant current received; means for providing an output signal coupled to said storage means and to said second amplifier; and means for providing feedback between said signal receiving means and said output means for controlling the amplitude of said terminal voltage.
Claim 5
Dependent Claim
148 words
A non-linear filter for attenuating spurious electronic signals, the filter comprising: means for receiving the signal to be attenuated; a first amplifier coupled to said signal receiving means for amplifying the signals to be attenuated and including means for providing the amplified signals as double-ended signals; a second amplifier coupled to said first amplifier and to receive said double-ended signals for providing a single-ended output signal, said second amplifier including a constant current source for providing a constant current; storage means coupled to said second amplifier and to receive at least a portion of said constant current for producing a terminal voltage thereacross in accordance with said constant current received; means for providing an output signal coupled to said storage means and to said second amplifier; and means for providing feedback between said signal receiving means and said output means for controlling the amplitude of said terminal voltage.
Claim 6
Dependent Claim
22 words
The filter according to claim 3 further comprising a current sink for receiving said single-ended output signal for sinking said constant current.
Claim 7
Dependent Claim
14 words
The filter according to claim 4 wherein said current sink comprises a current mirror.
Claim 8
Dependent Claim
20 words
The filter according to claim 3 further comprising a buffer amplifier for applying said terminal voltage to said output means.
References Cited (Backward Citations)
US3761787A
Cited
US3736517A
Cited
US3772604A
Cited
US3786363A
Cited
US3824496A
Cited
US3904978A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-08-06 | 1983-02-05 | 1983-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-08-06 | 1987-02-05 | 1987-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-08-06 | 1991-02-05 | 1991-08-07 | $7700.00 | Window Closed / Lapsed |