View rp500x-series datasheet:

＊RP500Z (WLCSP-6-P2) is the non-promotion product. As of March in 2014. RP500x SERIES 600mA∗ Step-down DC/DC Converter with Synchronous Rectifier NO.EA-155-111124 OUTLINE The RP500x Series are CMOS-based 600mA∗ step-down DC/DC Converters with synchronous rectifier. Each of these ICs consists of an oscillator, a switching control circuit, a reference voltage unit, an error amplifier, a soft-start circuit, protection circuits, UVLO circuit, switching transistors, and so on. A low ripple, high efficiency step-down DC/DC converter can be easily composed of this IC with only an inductor and capacitors. In terms of the output voltage, since the feedback resistances are built-in, the voltage is fixed internally. 0.1V step output can be set by laser-trim and 1.5% or 24m