TheLTC3623 is a high efficiency, monolithic synchronous buck regulator in which the output voltage is programmed with a single external resistor. The accurate internally generated 50µA current source on the ISET pin allows the user to program an output voltage from 0V to 0.5V below VIN. The user can also directly drive the ISET pin with an external voltage supply to program the converter’s VOUT. The VOUT voltage is fed directly back to the error amplifier to be regulated to the ISET voltage. The operating supply voltage range for the SVIN pin is from 15V down to 4V, while the PVIN pin’s voltage range is 15V down to 1.5V, making it suitable for dual Li-Ion batteries and for taking power from a 12V or 5V rail.