4.7 mOhm Rds(on) — the conduction-loss floor for a 25 V rail
The Texas Instruments CSD16342Q5A is a NexFET N-channel MOSFET rated for 25 V drain-source and 100 A continuous drain at the case. The 4.7 mOhm max on-resistance at 20 A with 8 V gate drive sets the conduction-loss floor in a synchronous buck or load switch — at 20 A the dissipation is under 2 W in the channel alone. The 7.1 nC gate charge at 4.5 V drive keeps switching losses manageable for 300–500 kHz converters without oversizing the gate driver.
8-VSONP package and thermal budget
The 3 W power dissipation at 25°C ambient (Ta) is the board-level limit — the actual headroom depends on the copper area and airflow. For a 12 V input, 1.2 V output buck at 20 A, the junction rise stays inside the -55°C to 150°C rating if the thermal pad is connected to a 1 oz inner-layer plane.
Active production, no obsolescence pressure
No NRND or last-time-buy notice is in effect. The BOM line is stable for current and new designs — no need to qualify a substitute or stockpile for an EOL window.