SIGNAL GENERATING CIRCUIT AND METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To easily and accurately set a minimum and a maximum pulse width of an output signal. SOLUTION: A PWM circuit consisting of a triangle wave generator 3, a D/A converter 4, and a comparator 5 or the like provides an output of a signal of a pulse width corresponding to input data DAT. A D-F/F 10 expands the period of the output signal by a prescribed multiple while keeping the duty of the output signal by using a clock CKM asynchronously with the output signal and a counter 14 measures the pulse width of the expanded signal. A correction arithmetic section 16 corrects data Nx1, Nx2 to set a minimum and a maximum pulse width of the received output signal based on the measured pulse width and a comparator 19 compares the measured pulse width with the corrected data Nx1, Nx2 and an adjustment data control section 20 adjusts the pulse width of the output signal based on the result of comparison.