Logarithmic analog to digital converter
US4625197A · kind A · utility
20Cited by
2References
13Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Sep 28, 1984 |
| Grant date | Nov 25, 1986 |
| Priority date | — |
| Expiry date | Sep 28, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/1235
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for converting an analog input signal to a digital output signal equal to the logarithm of the ratio of the input signal to a reference signal includes a method and apparatus for counting the cycles from a fixed frequency source for the time required for a capacitor to discharge through a resistor from a reference voltage to a calibration voltage; storing the result; counting the cycles from the same fixed frequency source for the time required for the capacitor to discharge through the resistor from the reference signal to the input signal and dividing the result by the stored result.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.