The BAT54S is a dual Schottky diode array in SOT-23-3 configured as common cathode from NXP. Each diode has a 30V reverse voltage rating, 200mA forward current, and 0.32V typical forward voltage at 1mA (compared to 0.7V for silicon PN junction diodes). The Schottky junction is formed by a metal-semiconductor (barrier) contact rather than a PN junction: majority carriers conduct immediately without the minority carrier storage that causes reverse recovery in PN diodes. This makes BAT54S essentially free of reverse recovery charge (approximately 5nC), ideal for high-speed switching and RF applications. The common-cathode configuration is commonly used for logic OR-ing (two supplies feeding one rail), signal clamping (both anodes connected to a signal line, cathode to VCC and GND for ESD protection), or as a full-wave rectifier pair. The low forward voltage minimizes power dissipation in OR-ing and rectification applications.