| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent the influence of electromagnetic noise occurring in an inductor on a photographed image by the step-up/step-down operation of a step-up/step-down switching circuit having the inductor. <P>SOLUTION: A power-supply circuit 5-1 of an imaging element module includes: a step-down circuit section 20 that steps down and outputs an input DC voltage by switching transistors 22 and 23 and an inductor 6; a linear regulator circuit section 30 that is provided in parallel to the step-down circuit section 20, and steps down and outputs the input DC voltage by a linear constant-voltage operation of a transistor 31; a step-up circuit section 40 that is connected in series to a former stage or a later stage of the step-down circuit section 20, and steps up and outputs the input DC voltage by a charge-pump operation or by switching the charge-pump operation and a step-up switching operation; and a regulation control section 56 that stops the operation of the step-down circuit section 20 during the photographing recording mode of the imaging element module and causes the linear regulator circuit section 30 to operate and to supply a constant voltage required for driving an imaging element. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
