US4525688A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oscilloscope signal input circuit including an attenuator
Assignee: Tektronix Inc
•
Filing: 1983-08-01
•
Granted: 1985-06-25
•
Expires: 2003-08-01
Abstract
Abstract An improved signal input circuit suitable for use in wideband oscilloscopes includes a high impedance controllable attenuator stage.
Inventors
- 👤 Desmond L. Murphy
- 👤 Warren K. Wimmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 00:20
CPC Classifications
H; H03; H03H; H03H7/00; H03H7/24
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
72 words
A signal input circuit, comprising: a first switch connected between an input and an output terminal; an attenuator network comprising a first parallel resistor-capacitor combination connected between said input and output terminals, and a second parallel resistor-capacitor combination connected between said output terminal and a common terminal; and a second switch connected between said common terminal and ground, wherein said first and second switches are operated in opposite state to each other.
Claim 2
Dependent Claim
72 words
A signal input circuit, comprising: a first switch connected between an input and an output terminal; an attenuator network comprising a first parallel resistor-capacitor combination connected between said input and output terminals, and a second parallel resistor-capacitor combination connected between said output terminal and a common terminal; and a second switch connected between said common terminal and ground, wherein said first and second switches are operated in opposite state to each other.
Claim 3
Dependent Claim
26 words
A signal input circuit in accordance with claim 1, further including an impedance converter comprising parallel AC and DC signal paths coupled to said output terminal.
References Cited (Backward Citations)
US3586989A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-06-24 | 1988-12-24 | 1989-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-24 | 1992-12-24 | 1993-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-24 | 1996-12-24 | 1997-06-25 | $7700.00 | Window Closed / Lapsed |