5 A PNP in a DPAK — the load-switch choice
The STD888T4 is a 30 V, 5 A PNP bipolar power transistor in a DPAK (TO-252-3) surface-mount package. It is a general-purpose PNP for medium-current switching and linear applications where the load sits below 5 A and the rail is 24 V or less.
30 V breakdown, 15 W dissipation — derating matters
The collector-emitter breakdown is rated at 30 V minimum, so a 24 V bus with 10 % margin (26.4 V) stays inside the ceiling. Without adequate pad area, the 15 W figure derates quickly. Vce saturation is specified at 1.2 V maximum with 500 mA base drive and 10 A collector current — that is the on-state voltage drop under heavy load. At the rated 5 A continuous collector current, the saturation voltage will be lower, but the 1.2 V figure at 10 A gives a worst-case conduction loss ceiling for thermal calculations.