Small-signal P-channel for load switching and signal-level work
It comes in a compact SC-70 / SOT-323 package (PG-SOT323), making it a fit for dense PCB layouts where a small-signal load switch, level shifter, or power-management gate is needed. On-resistance is specified at 8 Ohms maximum with 150 mA drain current and 10 V gate drive; the device can also be driven at 4.5 V for logic-level control, though Rds(on) will be higher than the 10 V figure. Gate charge is 1.5 nC at 10 V, and input capacitance is 19.1 pF at 25 V drain-source, keeping switching losses low in high-frequency or battery-operated circuits. Maximum power dissipation is 300 mW at ambient temperature, so thermal management is straightforward in this SOT-323 footprint.
Obsolete — plan your BOM transition
Infineon lists the BSS84PW as Obsolete. This means the manufacturer has stopped production and no further last-time-buy windows are open. For new designs or to keep an existing BOM running, a pin-compatible replacement must be qualified. The BSS84 (in SOT-23) is a common alternative but differs in package footprint; the BSS84PW is unique to the SOT-323 form factor. Sourcing for the BSS84PW now runs through independent distribution and surplus channels. If your line needs this exact package, we can source it to order; if a footprint change is acceptable, the BSS84 in SOT-23 is widely available and active.
This part is sized for signal-level switching (GPIO loads, small relays, LED drivers) where the load current stays under 50 mA and the voltage drop is tolerable. It is not suited for power distribution or high-current paths. Gate threshold is 2 V maximum at 20 µA drain current, so the device turns on fully with 3.3 V logic.