Logarithmic A=D converter - has true logarithmic characteristic and employs two standard generators

摘要

The logarithmic analogue to digital converter has a true logarithmic characteristic and provides high speed conversion, which is based on the generation of two groups of preset reference voltage levels and a pair of comparators providing a set of low weighting signal outputs excited by (n-1) lines representing the binary value for conversion. The reference levels are of a form defined by algebraic and trigonometric equations involving the conversion voltage standard, the logarithmic base and whole numbers varying between 1 and (n-1) and 1 and (r-1) respectively. The comparator outputs are other algebraic and trigonometric functions based on the above factors and factors e and m where e and m are the whole and fractional parts respectively of the logarithm to base k representing the input voltage Vi.