Dual Schottky in a SOT-323 for automotive and industrial clamping
The STMicroelectronics BAT54CWFILMY packs two Schottky barrier diodes in a common-cathode configuration inside a single SOT-323 package.
The 5 ns reverse recovery time is the key switching-speed spec. In a boost converter or a flyback snubber, that fast trr means the diode stops conducting almost immediately when the voltage reverses, minimising the reverse-recovery charge that would otherwise cause switching loss and ringing. Forward voltage is specified at 900 mV maximum at 100 mA — typical Schottky numbers, but the real thermal headroom comes from the 150°C junction rating. In a cramped ECU enclosure where ambient can hit 105°C, that margin matters for long-term reliability.
Common-cathode pair — where it saves board space
The 1 Pair Common Cathode configuration means the cathodes of both diodes are tied together internally. This is the standard topology for a dual Schottky used as a centre-tapped rectifier in a push-pull secondary, or as a single-package OR-ing diode pair where two independent anodes share a common output rail. One SOT-323 replaces two discrete SOD-123 diodes, cutting placement cost and board area roughly in half.
ROHS3 compliant.