US3594780A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital to analog converter having capacitor charged by input code pulses
Assignee: US Philips Corp
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Filing: 1968-09-03
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Granted: 1971-07-20
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Expires: 1988-09-03
Abstract
Abstract A digital to analog converter for sequential weighted pulse groups features a capacitor coupled to a resistor ladder network. The pulses are applied to a distributor and then to a pulse circuit which charges the capacitor from different points on the network depending upon the weighted value of the pulse.
Inventors
- 👤 Johannes Anton Greefkes
- 👤 Henricus Petrus Johannes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 01:45
CPC Classifications
H; H03; H03M; H03M1/00; H03M1/10; H03M1/1009
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
126 words
A converter for a group of weighted sequential pulses comprising a commutator means having a plurality of output lines for distributing said pulses among said lines; plurality of pulse circuits coupled to said output lines respectively an energy source coupled to said pulse circuits; a plurality of parallel coupled register networks coupled to said pulse circuits respectively; a capacitor coupled to one of said networks; and a sampler coupled to said capacitor and synchronized with said sequential pulses; means responsive to the occurrence of one of said pulses for directing energy from said energy source through a respective one of said pulse circuits and through said resistor network to charge said capacitor to a value depending upon the position of said pulse in said pulse group.
Claim 2
Dependent Claim
126 words
A converter for a group of weighted sequential pulses comprising a commutator means having a plurality of output lines for distributing said pulses among said lines; plurality of pulse circuits coupled to said output lines respectively an energy source coupled to said pulse circuits; a plurality of parallel coupled register networks coupled to said pulse circuits respectively; a capacitor coupled to one of said networks; and a sampler coupled to said capacitor and synchronized with said sequential pulses; means responsive to the occurrence of one of said pulses for directing energy from said energy source through a respective one of said pulse circuits and through said resistor network to charge said capacitor to a value depending upon the position of said pulse in said pulse group.
Claim 3
Dependent Claim
73 words
A converter as claimed in claim 1 wherein each of said pulse circuits comprises transistor having two conduction and a control electrode, said control electrode being coupled to one of said output lines and coupled to receive blocking voltage, said conduction electrodes being coupled to said energy source and said resistor network respectively; and a common resistor coupled between said energy source and one of said conduction electrodes in all of said transistors.
Claim 4
Dependent Claim
35 words
A converter as claimed in claim 1 wherein said parallel coupled register networks comprise ladder network and a terminal resistor, the attenuation ratio between any two adjacent sections of said ladder network being a constant.
Claim 5
Dependent Claim
13 words
A converter as claimed in claim 1 wherein said capacitor comprises variable capacitor.
Claim 6
Dependent Claim
28 words
A converter as claimed in claim 1 wherein said pulse circuits are coupled to said respective resistor networks in accordance with the weight of the pulses applied thereto.
Claim 7
Dependent Claim
30 words
A converter s claimed in claim 1 wherein said capacitor and resistor network have time constant substantially equal to the time duration of said pulse group plus the sample time.
Claim 8
Dependent Claim
44 words
A converter as claimed in claim 3 wherein said attenuation ratio substantially equals 2 exp (T1/R1C1), wherein T1is the time between successive pulses within a group, C1is the capacitance of said capacitor, and R1 is the equivalent resistance of said parallel coupled resistor networks.
Claim 9
Dependent Claim
60 words
A converter as claimed in claim 1 further comprising a reference voltage generator; a difference producer having inputs coupled to said reference voltage generator and said capacitor respectively, and an output; a pulse modulator having an input coupled to said difference signal producer output and an output coupled to said commutator means, a pulse generator coupled to said pulse modulator.
Claim 10
Dependent Claim
48 words
A converter as claimed in claim 8 wherein said reference voltage generator comprises second capacitor, a third resistor coupled in parallel with said second capacitor, a voltage source, and a sampler coupled between said second capacitor and said voltage source, said sampler being synchronized with said pulse generator.
Claim 11
Dependent Claim
41 words
A converter is claimed in claim 8 herein during the occurrence of the first pulse of said pulse group the voltage of said reference voltage generator substantially equals the weight factor of said first pulse multiplied by the coding unit E.
Claim 12
Dependent Claim
55 words
A converter as claimed in claim 8 wherein the voLtage of said reference pulse generator decreases between successive pulse by a factor 2 exp (Tby 1RC1), wherein T1 is the time between successive pulses C1 is the capacitance of said first recited capacitor, and R1 is the equivalent resistance of said parallel coupled resistor networks.
References Cited (Backward Citations)
US2807715A
Cited
US3184734A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-19 | 1975-01-18 | 1975-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-19 | 1979-01-18 | 1979-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-19 | 1983-01-18 | 1983-07-20 | $7700.00 | Window Closed / Lapsed |