DIGITAL SIGNAL DUTY RATIO DETECTOR CIRCUIT

摘要

PROBLEM TO BE SOLVED: To detect a duty ratio of a digital signal with a small error. SOLUTION: An N-bit shifter shifts a data signal of a first counter by N bits, and detects a more significant N-bit data signal. An adder stores less significant N-bit signal of the data signal, and generates a carry when the signal becomes the data signal of more significant N bits. The number of pulses applied to a third counter during an L level (low level) period of an n period of the digital signal is counted according to a second clock signal obtained by comparing a correction data signal obtained by integrating the carry from the adder with the more significant N-bit data signal with the data signal of a second counter to obtain the duty ratio.