The XC9252 series is a 30V operation step-down DC/DC controller IC. The external P-ch driver transistor is used to achieve a stable operation under low input voltage. Low ESR capacitors such as ceramic capacitors can be used for the load capacitor (CL). A 0.8V reference voltage source is incorporated, and the output voltage can be set freely from 1.5V using external resistors (RFB1, RFB2). 280kHz to 550kHz can be selected for the switching frequency by connecting an external resistor to the ROSC pin. The generation of unneeded noise can be reduced by this synchronization with an external CLK within ±25% of the internal clock using the MODE/SYNC pin. In automatic PWM/PFM control, the IC operates by PFM control when the load is light to achieve high efficiency over the full load range from light to heavy. The soft start time can be set as desired by adding an external capacitance to the SS pin. With the built-in UVLO function, the driver transistor is forced OFF when input voltage becomes 2.5V or lower. Internal protection circuits include over current protection, short-circuit protection, and thermal shutdown circuits to enable safe use