40 V / 100 A N-channel — the conduction-loss floor
The N0434N-S23-AY is a 40 V, 100 A N-channel power MOSFET in a TO-262 through-hole package, built on a standard planar MOSFET process. At 100 A continuous drain current, the package dissipation ceiling of 119 W at the case (Tc) tells you the thermal path to the heatsink is the real limit, not the silicon.
Gate charge and switching budget
Total gate charge is 100 nC at 10 V, with an input capacitance of 5550 pF at 25 V drain-source. For a 100 kHz switching frequency, the gate-drive power is roughly Qg × Vgs × fsw = 100 nC × 10 V × 100 kHz = 100 mW, well within a standard gate-driver IC's capability. The 10 V drive voltage is mandatory to achieve the rated Rds(on) — driving at 5 V leaves the channel partially enhanced and the on-resistance climbs.
Package and thermal reality
The TO-262-3 (I²Pak variant with long leads) is a through-hole package intended for a heatsink mount — the 1.5 W dissipation in still air (Ta) versus 119 W at the case (Tc) is the delta between no heatsink and a proper thermal interface. The 150°C maximum junction temperature is standard for this class; the practical junction temperature for a 100 A pulse is limited by the package's thermal resistance, not the die. The long leads on the TO-262 allow the part to sit above the PCB for airflow or to reach a chassis-mount heatsink.
Lifecycle and compliance
It is ROHS3 compliant, with no halogen or lead restrictions beyond the standard exemptions. The ±20 V maximum gate-source voltage is a hard limit; the drive circuit must clamp transients below this rail or the gate oxide ruptures.