The Infineon BAV 99 E6433 is a dual series-connected switching diode in a standard SOT-23-3 surface-mount package. The 4 ns reverse recovery time makes it suited for high-speed switching, clamping, and logic-level steering applications where fast turn-off is needed — think relay coil suppression, flyback snubbing on a 24 V industrial bus, or protecting a comparator input from overvoltage transients. The SOT-23 footprint is a common board-level component that reflow-solders without special handling; the PG-SOT23 supplier package variant is the Infineon-specific marking.
The BAV 99 E6433 carries an official lifecycle status of Obsolete.
The 80 V reverse voltage rating sets the maximum DC or repetitive peak reverse voltage the diode can block — adequate for 48 V telecom rails or 24 V industrial supplies with margin, but not for 120 V AC rectification. The 4 ns reverse recovery time is the headline switching spec: it determines how fast the diode can transition from forward conduction to reverse blocking, directly affecting switching losses in a 100 kHz+ converter or the clamping bandwidth in a high-speed data line protector. Forward voltage drop is 1.25 V at 150 mA — typical for a small-signal silicon diode, so power dissipation at 200 mA continuous in free air on a standard PCB will be about 250 mW, which the SOT-23 package handles with reasonable junction temperature margin up to 150°C.