US4009399A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gated ramp generator
Assignee: Tektronix Inc
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Filing: 1976-02-05
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Granted: 1977-02-22
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Expires: 1996-02-05
Abstract
Abstract A precision ramp voltage generator is provided which exhibits exceptionally small start-up aberrations and simultaneously maintains baseline stability. The perturbations in the output are corrected by an increase or decrease in an error current developed via feedback means to charge or discharge a timing capacitor in the direction necessary to maintain the desired baseline, whereas start-up aberrations are minimized by effecting a very fast current switch to a timing element from a current source to a current sink of greater magnitude.
Inventors
- 👤 Bruce Edward Hofer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:51
CPC Classifications
H; H03; H03K; H03K4/00; H03K4/06; H03K4/08; H03K4/48; H03K4/50
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
139 words
A gated ramp voltage generator, comprising: a current source for providing a first current; capacitor means connected to said current source for developing the ramp voltage thereacross in response to current applied thereto; comparator means having a first input coupled to receive the ramp voltage and a second input connected to a reference voltage source, said comparator means producing a second current at the output thereof which is proportional to the difference in amplitude between the ramp voltage and said reference voltage; and current steering means coupled to both said capacitor means and said comparator means for steering to said capacitor means said first and said second currents to produce the ramp voltage, said current steering means including means for gating said first and said second currents to cause the ramp voltage developed to be a gated ramp voltage.
Claim 2
Dependent Claim
139 words
A gated ramp voltage generator, comprising: a current source for providing a first current; capacitor means connected to said current source for developing the ramp voltage thereacross in response to current applied thereto; comparator means having a first input coupled to receive the ramp voltage and a second input connected to a reference voltage source, said comparator means producing a second current at the output thereof which is proportional to the difference in amplitude between the ramp voltage and said reference voltage; and current steering means coupled to both said capacitor means and said comparator means for steering to said capacitor means said first and said second currents to produce the ramp voltage, said current steering means including means for gating said first and said second currents to cause the ramp voltage developed to be a gated ramp voltage.
Claim 3
Dependent Claim
30 words
The generator according to claim 1 further comprising a voltage follower amplifier means disposed between said first input and said capacitor for coupling the ramp voltage to said comparator means.
Claim 4
Dependent Claim
19 words
The generator according to claim 1 where said second current maintains the base line level of the ramp voltage.
Claim 5
Dependent Claim
131 words
The generator according to claim 1 wherein said current steering means including means for gating further comprises: current sink means for sinking substantially more current than both said first and said second currents; differential amplifier means including first and second transistors having their emitters coupled to said current sink means for selectively steering both said first and said second currents to said current sink means; unipolar device means coupled between the collectors of said first and said second transistors and also being directly coupled between said capacitor means and said output of said comparator means for selectively steering both said first and said second currents to said capacitor means; and control means for controlling the bases of said transistors to gate said first and said second currents to said capacitor means.
Claim 6
Dependent Claim
23 words
The generator according to claim 4 further comprising an additional unipolar device means coupled to one of said collectors for preventing saturation thereof.
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) | 1980-02-22 | 1980-08-23 | 1981-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-22 | 1984-08-23 | 1985-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-22 | 1988-08-23 | 1989-02-22 | $7700.00 | Window Closed / Lapsed |