Patent ID: 6313621
Filing Date: 2001-11-06
Classification: G01R,H03D,H03L

Abstract:
A method for determining a phase difference between first and second timing signals, said first and second timing signals being of a digital nature and a pulse period of the second timing signal being known, comprising the steps of:a) feeding the first timing signal to a first delay element of a plurality of serially connected delay elements, said plurality of serially connected delay elements forming a delay line so that the first timing signal passes through individual ones of said delay elements of the delay line in succession;b) determining a first total number of delay elements of the delay line that are passed through by the first timing signal during a time-span between a timing pulse edge of the first timing signal and a subsequent timing pulse edge with a same polarity of the second timing signal;c) determining a second total number of delay elements of the delay line that are passed through by the first timing signal between a further timing pulse edge and a subsequent further timing pulse edge with a same polarity of the second timing signal;d) determining a delay time of each delay element of the delay line as a quotient of the pulse period of the second timing signal and the second total number of delay elements which was determined in step c); ande) determining a phase difference between the first and second timing signals dependent on the first total number of delay elements which was determined in step b) and on the delay time of each delay element of the delay line which was determined in step d); whereinin step a) the first timing signal is fed back to the first delay element of the delay line subsequent to passing through all individual delay elements of the delay line so that the delay line is passed through multiple times, and counting said passing through all individual delay elements of the delay line as a number of complete passes of the first timing signal through the delay line,in step b) the first total number of delay elements is determined in additional consideration of the number of complete passes of the first timing signal through the delay line, said number of complete passes of the first timing signal through the delay line being determined by a pass-through determiner, andin step c) the second total number of delay elements is determined in additional consideration of the number of passes of the first timing signal through the delay line at the determination time of the second total number of delay elements.