The PBSS4021NX is a 7A NPN breakthrough-in small signal (BISS) Transistor in a medium power and flat lead surface-mount plastic package. It offers die pad for good heat transfer.
Very low collector-emitter saturation voltage VCEsat
High collector current capability IC and ICM
High collector current gain (hFE) at high IC
High energy efficiency due to less heat generation
Smaller required printed-circuit board (PCB) area than for conventional transistors