Dual complementary transistor in a compact TSOT-23-5
The ROHM Semiconductor QSZ2TR packs a matched NPN and PNP pair in a single TSMT5 (TSOT-23-5) package, with the emitters tied together internally. This emitter-coupled configuration is useful for push-pull output stages, H-bridge low-side drivers, and complementary signal switching where you want the two devices to track thermally. Collector current is rated 1.5A per transistor, with a VCEO of 30V — enough for 12V and 24V rail work with healthy derating. Transition frequency runs 300 MHz on the NPN side and 280 MHz on the PNP, so it handles PWM into the low-MHz range without excessive switching loss. DC current gain minimum is 270 at 100 mA, giving good drive efficiency from logic-level base currents.
Package and reflow considerations
The TSOT-23-5 footprint is small — roughly 2.9 mm × 2.8 mm — and the thin profile (1.1 mm max) suits low-profile assemblies. It's a surface-mount part, so check your pick-and-place nozzle for the 5-pin layout; tombstoning risk is low with the two larger collector pads on opposite sides. The 1.25W power dissipation limit assumes good board-level heat sinking; if you're running both transistors near 1.5 A simultaneously, you'll need to keep the junction at or below 150°C. No MSL rating is listed in the record, so treat it as MSL 1 by default unless the reel label says otherwise — bake only if the package has visible moisture exposure.
Sourcing and production status
ROHS3 compliant. If you're dual-sourcing, the QS5Y1TR is a close functional match: same 1.25W power rating, same 30V VCEO, same NPN/PNP complementary pair in a similar TSOP-6 package, though its Vce(sat) is 400 mV vs 350 mV at the same 1A test point.