Analog to digital converter
US4683457A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 29, 1986 |
| Grant date | Jul 28, 1987 |
| Priority date | — |
| Expiry date | Apr 29, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/64
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The disclosure is directed to an analog-digital converter which includes a source having an output of fixed frequency time-spaced pulses. An oscillator having an output of time-spaced pulses, harmonically related to pulses from the source, is comprised of a plurality of digital gates connected serially in a loop. At least one of the digital gates includes impedance means such as a resister or capacitor, responsive to an analog condition to form a modulator. Change in the value of the impedance changes the time constant of the modulator to effect a change in the time-spaced pulses related to the instantaneous amplitude of the analog condition. The outputs of the source and the oscillator are applied to a comparator. Means responsive to the comparator is employed to correct the oscillator time-spaced pulses toward an in phase state relative to the time-spaced pulses from the source. A digital signal is produced whose value is proportional to the correction made to the oscillator time-spaced pulses and is thus representative of the instantaneous value of the analog condition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.