What the BAT41 is and where it fits
The BAT41 is a Schottky barrier rectifier diode from STMicroelectronics, rated for 100 V reverse voltage and 100 mA average rectified current. It comes in a DO-35 axial-lead package for through-hole mounting. The Schottky construction gives a forward voltage drop of 450 mV at 1 mA, which keeps conduction losses low in low-voltage circuits. Typical applications include small-signal rectification, freewheeling diodes in relay and solenoid drivers, polarity protection on low-current rails, and high-speed switching where reverse-recovery time matters. The junction temperature range of -65°C to 125°C covers industrial and some automotive under-hood environments.
100 V reverse voltage — what it means for the rail
The 100 V DC reverse voltage rating means this diode can block up to 100 V without breaking down.
100 mA average current — small-signal class
The 100 mA average rectified current (Io) places the BAT41 firmly in the small-signal category. It is sized for signal diodes, gate-drive circuits, and low-power auxiliary rails — not for main power rectification. If your load pulls 200 mA continuous, this part is undersized. The speed rating of "Small Signal =< 200 mA (Io), Any Speed" confirms it is intended for switching applications where the average current stays under 200 mA.
Forward voltage and leakage — the Schottky trade-off
The 450 mV forward drop at 1 mA is the main reason to pick a Schottky over a standard silicon diode — it wastes less voltage and heat in low-voltage paths. The reverse leakage is 100 nA at 50 V.
Package and mounting — DO-35 axial
The DO-35 axial package is a through-hole part with wire leads. It solders into a PCB or a terminal strip. Polarity is marked by a cathode band on the body — easy to get right on site with a visual check.
Lifecycle and sourcing
The BAT41 is listed as Active in production with ROHS3 compliance. No end-of-life notice or last-time-buy is on record. It is a standard catalog part available through independent distribution.