The variable delay circuit for calibration operation by calibration method and a calibration method of the variable delay circuit

摘要

PROBLEM TO BE SOLVED: To execute the calibration of delay time in a short time by updating a calibration table with a control signal value at which an error becomes smaller whenever the delay time of a variable delay circuit that is set by each control signal is measured. ;SOLUTION: An integer value k made by dividing a measured delay time D_i by a nominal delay step d_s and errors R_k' and R_k+1' to two adjacent nominal delays d_sk and d_s(k+1) are calculated at the same time with measuring a delay time of a variable delay circuit. And, when a constant error R_k' is an error R_k held in the k-th line of a calibration table or less, the R_k' and CC_i are overwritten as new data R_k and CC_i in the k-th line and when it is a measurement error R_k+1 or less, (R_k+1' and CC_i) are overwritten an new data (R_k+1 and CC_i) in the (k+1)-th line. According to the processing, the calibration of the delay time that is desired for when the measurement of delay time about the whole control signal values CC_i and the update of the calibration table have been finished is completed.;COPYRIGHT: (C)1999,JPO