求一个5V变9V的电路和元件说明

调节电阻就可以达到9V
The?output?voltage?is?set?by?two?external?resistors?(R2
【求一个5V变9V的电路和元件说明】
and?R3,?Figures?2,?3,?4,?and?5).?First?select?a?value?for
R3?in?the?10kto?1Mrange.?R2?is?then?given?by:
R2?=?R3?[(VOUT?/?VREF)?–?1]
where?VREF?is?1.25V.