| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a power supply unit capable of facilitating adjustment of a driving voltage using voltage information applied to a current control portion and extremely reducing power consumption in the current control unit although the amount of the current to be supplied to the load is adjusted by PWM control. <P>SOLUTION: This power supply unit includes: a power supply portion provided on the upstream side of the load and for supplying the driving voltage to the load; the current control portion provided on the downstream side of the load and for introducing the current controlled to a predetermined amount from power supply portion through the load, in which the current control portion adjusts a duty ratio of the current by the PWM control, a sample hold portion for sampling and holding the voltage value on the downstream side of the load and the upstream side of the current control portion during on-duty in the PWM control, and a voltage adjusting portion for adjusting the value of the driving voltage corresponding to the hold value of the sample hold portion. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
