The Infineon BAV99SE6327BTSA1 is a dual series-connected standard switching diode in a PG-SOT363 surface-mount package. It pairs two diodes in series internally, saving board space compared to two discrete SOD-323 or SOT-23 devices. With an 80 V reverse voltage rating and 200 mA average forward current per diode, it handles 48 V and 60 V bus clamping, relay coil suppression, and general-purpose high-speed switching in industrial and telecom boards.
4 ns reverse recovery — the switching-speed spec that matters
The 4 ns reverse recovery time (trr) is the headline switching parameter for this diode pair. It means the diode recovers from forward conduction to blocking in under 5 ns, which is fast enough for switch-mode power supply snubbers, high-speed logic clamping, and signal-line protection where the edge rate is in the nanosecond range. Slower diodes (trr > 50 ns) would ring or overheat in the same circuit.
80 V reverse voltage, 150 nA leakage — margin for industrial rails
The 80 V maximum DC reverse voltage gives comfortable derating headroom on 48 V telecom rails (60% margin) and 24 V industrial supplies (70% margin). Reverse leakage is specified at 150 nA at 70 V reverse bias — low enough that it won't disturb high-impedance sense nodes or precision analog inputs. The 1.25 V forward drop at 150 mA is typical for a small-signal silicon switching diode; the junction temperature rating reaches 150°C, consistent with industrial ambient ranges.
Obsolete — sourcing through independent distribution
Infineon lists the BAV99SE6327BTSA1 as obsolete. For BOM lines that require this package marking and pinout, procurement runs through independent distribution and surplus channel. Date-code provenance matters here — buyers should verify fresh stock against the original Infineon specification.