| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a PWM control system which varies a PWM term, sets a duty ratio in accordance with an operating status of a load, and forms the duty ratio with a full logic. <P>SOLUTION: A PWM control circuit comprises: a PWM fundamental wave generating means 12 for frequency-dividing a fundamental frequency signal to form a PWM fundamental wave; a PWM term setting means 22 for setting a PWM term on the basis of the PWM fundamental wave; a duty ratio forming means 23 for forming a duty ratio (N/M:N≤M, wherein M is a maximum clock number) within the PWM term; and a PWM control signal output means for outputting a PWM control signal with the duty ratio to a driving circuit of a load. <P>COPYRIGHT: (C)2009,JPO&INPIT |
