30 V, 200 mA Schottky for low-voltage rail clamping and fast rectification
The BAT43 is a small-signal Schottky diode rated for 30 V DC reverse voltage and 200 mA average rectified current — a common choice for low-voltage rail protection, polarity protection, and high-frequency rectification in battery-powered or signal-level circuits. Its 5 ns reverse recovery time (trr) keeps switching losses low in DC-DC converter snubbers and flyback catch-diode positions, where a slower PN-junction diode would ring or overheat. The DO-35 axial-lead package (DO-204AH) suits through-hole assembly, breadboard prototyping, and hand-solder rework — a footprint that mates with legacy board layouts and high-reliability point-to-point wiring.
Reverse leakage is 500 nA at 25 V — low enough to avoid draining a battery in a reverse-blocking or OR-ing application, but note that leakage doubles with every 10 °C rise above 25 °C junction temperature. Capacitance is 7 pF at 1 V reverse bias, 1 MHz — a light capacitive load for a high-speed signal line or RF detector, but not negligible at UHF frequencies where a few pF shifts the impedance match.