View ln2351 datasheet:

Super-Small Package VFM Control Step-up Switching Regulator LN2351 Series SUPER-SMALL PACKAGE VFM CONTROL STEP-UP SWITCHING REGULATOR LN2351 SERIES ■ DESCRIPTION The LN2351 Series is a CMOS PFM-control step-up switching regulator that mainly consists of a reference voltage source, an oscillator, and a comparator. enabling products with a low ripple over a wide range, high efficiency, and high output current. Products with a fixed duty ratio of 75 % （Lower Output Voltage） or 88%(Higher Output Voltage) are also available. With the LN2351 Series, a step-up switching regulator can be configured by using an external coil, capacitor, and diode. A protection circuit turns off the built-in MOS FET when the voltage at the CONT pin exceeds the limit to prevent it from