Analog-to-digital converter recalibration method and apparatus
US4118698A · kind A · utility
Inventor
Key dates
| Filing date | Jun 10, 1977 |
| Grant date | Oct 3, 1978 |
| Priority date | — |
| Expiry date | Jun 10, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/56
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Automatic recalibration and testing of the accuracy of an analog-to-digital converter is accomplished in a converter of the type that compares the analog input signal with a linearly changing ramp referene signal and measures the time interval required for the magnitude of the reference signal to reach the level of the analog input signal from an initial level. In the invention, the linearly changing ramp reference signal is allowed to continue beyond the end of the converter's measuring phase and is thereupon compared with a datum voltage by a comparator which determines when equality between the two occurs. At the end of the measuring phase, a control pulse of fixed duration is generated and if the time of occurrence of equality is within the duration of that pulse, the converter is then operating within a suitable range of accuracy. The converter is automatically recalibrated by adjustment of the reference signal to make equality of the reference signal and the voltage datum occur in the center of the duration of the control pulse.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.