Two Schottky diodes in a SOT-666 — what you get
The STMicroelectronics BAT54-09P6FILM is a dual Schottky diode array containing two independent, electrically isolated diodes in a single SOT-666 package. Each diode is rated for 300 mA of average rectified current (DC) with a 40 V maximum reverse voltage. The 5 ns reverse recovery time (trr) makes it suitable for high-speed switching applications like polarity protection, OR-ing, and clamping in low-voltage DC rails.
Obsolete — plan the BOM move now
5 ns reverse recovery — fast enough for most switching rails
The 5 ns trr is typical for a small-signal Schottky at this current level. It handles switching frequencies well into the MHz range without significant reverse-recovery losses, which matters for DC-DC converter snubbers, flyback diode positions, and high-speed logic-level clamping. The 900 mV forward voltage drop at 100 mA is on the higher side for a Schottky — expect about 0.4 V to 0.5 V at lower forward currents typical of signal diode use.
SOT-666 footprint — small, but watch the pad layout
The SOT-666 package is a 1.6 mm × 1.6 mm body with six leads — two per diode plus two common cathode? Actually, the BAT54-09P6FILM uses the SOT-666 pinout for two independent diodes. The datasheet (available on request) shows the exact pad pattern.