The B0503S-1W is a 4-pin SIP (single in-line package) power module manufactured by JETEKPS. It contains a Schottky barrier diode, a positive-temperature-coefficient device (PTC) and a ceramic capacitor. The module is compliant with RoHS (Restriction of Hazardous Substances) requirements, making it a safe and reliable way to supply power to a variety of devices. It supports a voltage range of 2.8V to 6.5V with a maximum current output of 1A. The Schottky barrier diode prevents reverse polarity connection, while the PTC ensures current limiting and short circuit protection. The ceramic capacitor improves the dynamic performance of the current output. This module is ideal for use in a wide range of applications, such as automotive, industrial, audio, electronic ballasts, and lighting.