80 V N-channel in a 3.3 mm × 3.3 mm footprint
The BSZ340N08NS3GATMA1 is an Infineon OptiMOS N-channel MOSFET rated for 80 V drain-source with a continuous drain current of 23 A at the case (6 A at ambient). The PG-TSDSON-8 package — 3.3 mm × 3.3 mm with an exposed pad — puts a 23 A switch on a footprint smaller than an SOT-23, which is the whole point of the OptiMOS trench topology. Rds(on) is 34 mOhm maximum at 12 A with 10 V gate drive. That 34 mOhm at 23 A comes to 18 W conduction loss at the die — the 32 W package limit at the case leaves about 14 W headroom for switching loss, so this part is specced for hard-switched DC-DC and motor-drive outputs where the duty cycle keeps the average current below 12 A.
Gate charge and switching speed
Total gate charge at 10 V is 9.1 nC, and input capacitance is 630 pF at 40 V drain. For a 500 kHz buck converter, the gate drive current needed is about 4.5 mA average — easily handled by a standard 1 A gate driver. The low Qg relative to the 23 A rating means the switching losses don't eat the conduction budget at moderate frequencies. The threshold voltage window (3.5 V max at 12 µA) means 5 V logic from a 3.3 V MCU won't fully enhance the channel — the datasheet calls for 6 V or 10 V drive to hit the rated Rds(on). A 5 V gate driver or a 12 V rail is the practical choice for this part.
Temperature range and thermal handling
Junction temperature range is -55°C to 150°C, covering automotive under-hood and industrial motor-drive environments. The 2.1 W dissipation at ambient is a board-limited figure — the real thermal path is through the exposed pad to the PCB copper. The 32 W at the case assumes a thermal interface to a heatsink or a multi-layer board with thermal vias.