Schottky 40 V, 350 mA — low-loss rectification for small-signal rails
The STMicroelectronics BAT48ZFILM is a small-signal Schottky diode rated 40 V reverse voltage and 350 mA average rectified current, targeted at low-power DC-DC converter freewheeling, reverse-polarity protection, and OR-ing diodes in portable or battery-powered equipment. Its forward voltage drop is 750 mV maximum at 200 mA, which keeps conduction losses manageable in the sub-500 mA load range.
Switching speed: ≤500 ns recovery at >200 mA
The BAT48ZFILM is classified as a fast recovery diode with recovery time ≤500 ns at a forward current above 200 mA. This is adequate for line-frequency rectification and low-frequency (tens of kHz) flyback converters, but not for MHz-range switching regulators where a SiC or ultra-fast diode would be needed. Junction capacitance is 30 pF at 0 V, 1 MHz — low enough to avoid significant ringing in lightly damped snubber networks.
Surface-mount SOD-123 — standard reflow footprint
The SOD-123 package (supplier device package SOD-123) is a widely used small outline package with a 0.50 mm lead pitch and a low profile (~1.1 mm height). It mounts on standard FR-4 with no exposed pad; the cathode is marked by a band on the body.