| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a dimming device capable of finely adjusting brightness up to regions in which on-duty of a burst dimming signal is minute. <P>SOLUTION: A dimming device comprises a converter circuit which includes a first switching element FET1 and supplies electric power to a LED and a second switching element FET2 connected in series to the LED. The converter circuit includes: an error amplifier 12 which outputs a feedback control signal based on the current flowing the LED; a control circuit 10 which turns on/off the first switching element based on the feedback control signal and burst dimming signal; and a charge holding part C2 connected to an output terminal of the error amplifier and an input terminal of the control circuit. The second switching element controls the current flowing in the LED in synchronization with the burst dimming signal. The converter circuit further includes switch parts Q1, Q2 which separate and connect the error amplifier, control circuit, and charge holding part in synchronization with the burst dimming signal. <P>COPYRIGHT: (C)2012,JPO&INPIT |
