| 摘要 |
PROBLEM TO BE SOLVED: To provide an LED control device capable of suppressing the flickering of the LED luminance. SOLUTION: For example, a duty detection circuit DTDET1 is provided for detecting a duty from a PWM signal PWM_IN which is a specification signal for the LED luminance, and outputting a duty setting signal DTOUT. The LED luminance is controlled by a PWM signal that has the duty based on the DTOUT. The DTDET1 detects a cycle of the PWM_IN and a high level period by a cycle detection counter circuit CCUNT and a high level period detection counter circuit HCUNT respectively, and outputs an interim duty setting signal DVAL by calculating the detection result with a dividing circuit LOG_DIV. Only when a difference value between the DTOUT and the DVAL is larger than a predetermined value SDAT, the DTOUT is updated with the DVAL using a digital comparator block DCMP_BK. COPYRIGHT: (C)2011,JPO&INPIT
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