This part is a kind of semiconductor called XL1507.

Function of this product has 3A 150KHz 30V Buck DC to DC Converter.

Manufacturers : XLSEMI

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Some of the text within the PDF file :

XLSEMI 3A 150KHz 30V Buck DC to DC Converter Features „ „ „ „ „ Datasheet XL1507 General Description The XL1507 is a 150 KHz fixed frequency PWM buck (step-down) DC/DC converter, capable of driving a 3A load with high efficiency, low ripple and excellent line and load regulation. Requiring a minimum number of external components, the regulator is simple to use and include internal frequency compensation and a fixed-frequency oscillator. The PWM control circuit is able to adjust the duty ratio linearly from 0 to 100%. An enable function, an over current protection function and a short circuit protection function are built inside. When OCP or SCP happens, the operation frequency will be reduced from 150KHz to 50KHz. An internal compensation block is built in to minimize external compon [ ... ]

XL1507 PDF Datasheet Download