US3862435A
Expired / Lapsed
US
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Digital shift register
Assignee: US Philips Corp
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Filing: 1973-08-07
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Granted: 1975-01-21
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Expires: 1993-08-07
Abstract
Abstract A digital shift register comprising a series connection of a number of source-followers, the input of each source-follower being connected both to a storage capacitance and to an electronic switch for establishing the reference level at the relevant capacitance. Between the inputs of at least some of the source-followers and the associated clock lines variable capacitances are included. The variable capacitances serve to compensate for the voltage losses occurring the source-followers as a result of the threshold voltages of the transistors employed in said source-followers.
Inventors
- 👤 Roelof Herman Willem Salters
- 👤 Lieuwe Boonstra
- 👤 Cornelis Willem Lambrechtse
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 02:03
CPC Classifications
H; H10; H10D; H10D84/00; H10D84/80; H10D84/811; G; G11; G11C; G11C19/00; G11C19/18; G11C19/182; G11C19/184
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
171 words
A digital shifter register, of the type comprising a chain of signal-followers, having control inputs and main conduction paths, the control input of each signal-follower being connected both to a storage capacitance and to an electronic switch for establishing a reference level at the associated storage capacitance, wherein the current through the main conduction path of each signal-follower varies as a function of potential in excess of a threshold level between the control input and one end of the main conducting path, the signal-followers being connected in cascade through the control inputs and said one ends of said main conducting paths, two adjacent signal followers being connected to two separate clock lines, the improvement comprising voltage variable capacitances connecting the control input of at least one of the signal followers to the clock lines which are connected thereto, said variable capacitances having higher capacitance in response to potentials thereacross exceeding the threshold level of the signal follower connected thereto then the capacitance resulting from a potential lower than said threshold level.
Claim 2
Dependent Claim
171 words
A digital shifter register, of the type comprising a chain of signal-followers, having control inputs and main conduction paths, the control input of each signal-follower being connected both to a storage capacitance and to an electronic switch for establishing a reference level at the associated storage capacitance, wherein the current through the main conduction path of each signal-follower varies as a function of potential in excess of a threshold level between the control input and one end of the main conducting path, the signal-followers being connected in cascade through the control inputs and said one ends of said main conducting paths, two adjacent signal followers being connected to two separate clock lines, the improvement comprising voltage variable capacitances connecting the control input of at least one of the signal followers to the clock lines which are connected thereto, said variable capacitances having higher capacitance in response to potentials thereacross exceeding the threshold level of the signal follower connected thereto then the capacitance resulting from a potential lower than said threshold level.
Claim 3
Dependent Claim
86 words
A digital shift register as claimed in claim 1, wherein the signal-followers are formed by field-effect transistors, the source electrode of each field-effect transistor being connected to the gate electrode of the next field-effect transistor, the drain electrodes of two consecutive field-effect transistors being connected to separate clock lines, characterized in that the electronic switches are constituted by the field-effect transistors, whose source electrodes are connected to a point of constant potential, the drain electrodes being connected to the source electrodes of the associated field-effect transistors.
Claim 4
Dependent Claim
24 words
A digital shift register as claimed in claim 2, wherein diodes connect the variable capacitances to the drain electrodes of the associated field-effect transistors.
Claim 5
Dependent Claim
32 words
A digital shift register as claimed in claim 2, wherein diodes connect the source electrodes of the field-effect transistors which form the emitters followers to the electronic switches which are connected thereto.
Claim 6
Dependent Claim
18 words
A digital shift register as claimed in claim 2 wherein the field-effect transistors are of the insulated-gate type.
Claim 7
Dependent Claim
18 words
A digital shift register as claimed in claim 1, wherein said register is integrated in a semiconductor body.
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) | 1978-01-20 | 1978-07-22 | 1979-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-20 | 1982-07-22 | 1983-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-20 | 1986-07-22 | 1987-01-21 | $7700.00 | Window Closed / Lapsed |