Dual PNP in a 1.6 mm × 1.6 mm footprint
The ROHM EMT51T2R packs two matched PNP transistors into a single SOT-563 package, saving board area compared to two discrete SOT-23s. Each transistor is rated for a collector current of 200 mA and a collector-emitter breakdown voltage of 20 V, with a transition frequency of 350 MHz — fast enough for signal switching and level translation up to a few tens of MHz. The 150 mW total power budget means the package relies on the PCB copper for heat spreading; keep the ambient derating in mind if both transistors conduct simultaneously near the current limit.
The minimum DC current gain of 120 at 1 mA collector current and 6 V collector-emitter is the spec that determines base drive margin in low-level switching. The 100 nA maximum collector cutoff current is tight enough that leakage won't pull down a high-impedance node at room temperature.
Package and mounting
The EMT51T2R is supplied in a SOT-563 package (also listed as SOT-666), with the supplier device designation EMT6. It is a surface-mount device intended for reflow assembly. The package is small — roughly 1.6 mm × 1.6 mm — so the PCB footprint and solder paste stencil aperture need careful sizing to avoid bridging between the six leads.
Lifecycle and compliance
The junction temperature rating of 150 °C is typical for general-purpose transistors and allows operation in warm environments as long as the total power dissipation stays within the 150 mW package limit.