RP504x series is a low supply current CMOS-based PWM/VFM step-down DC/DC converter with synchronous rectifier. RP504K/L can be switched from two control types by inputting signal to the MODE pin - forced PWM control or PWM/VFM auto switching control in which mode automatically switches to high-efficiency VFM mode in low output current. (RP504N Series can be selected from forced PWM control or PWM/VFM auto switching control.) RP504x includes a soft start circuit, an under-voltage lockout circuit (UVLO), and a latch protection circuit. By simply using an inductor and capacitors as external components, a high-efficiency step-down DC/DC converter can be easily configured. The small inductor (2.2μH) and output capacitor (4.7μH) can be used by the switching of 2.25MHz. In addition to SOT-23-5 and DFN1616-6B packages, a 1.2mm × 1.6mm DFN(PLP)1216-6B package is also available.