Patent ID: 8952638
Filing Date: 2015-02-10
Classification: G01R,H02P

Abstract:
1. A circuit for detecting a duty ratio of a pulse width modulation (PWM) signal, the circuit comprising: a counting unit counting a PWM signal; a detection indication determining unit determining whether a detection indication signal indicating a start of detection of the duty ratio of the PWM signal has been input; an edge detecting unit detecting a preset PWM edge of the PWM signal; and a duty calculating unit calculating the duty ratio of the PWM signal using a count value from the counting unit during a section from a k-th point in time (T(k)) (k indicates a natural number of 1 or more) at which the PWM edge is detected after it is determined that the detection indication signal has been input to a k+1-th point in time (T(k+1)) at which the PWM edge is detected after it is subsequently determined that the detection indication signal has been input.