Device identity and headline ratings
The IRF6637TRPBF: The pulsed drain current ceiling is 59 A, which governs the safe operating area for switching transients and inrush events.
On-resistance and conduction loss
Maximum on-resistance is 7.7 mOhm at Vgs = 10 V and Id = 14 A. This is the figure to use for steady-state conduction loss calculations at the rated continuous current. The Rds(on) increases with junction temperature per the normalized curve in the datasheet; at 150 °C junction the resistance roughly doubles, so the I²R loss budget must include the hot resistance, not the 25 °C value.
Gate drive and switching performance
Total gate charge Qg is 17 nC max at Vgs = 4.5 V. This is the charge the gate driver must source to turn the FET fully on. At a 500 kHz switching frequency, the average gate-drive current is 8.5 mA; at 1 MHz it reaches 17 mA. The gate threshold voltage is 2.35 V max at Id = 250 µA, so a 5 V logic-level drive provides adequate overdrive margin. The maximum gate-source voltage rating is ±20 V, which accommodates most standard gate-drive rails without external clamping.
Thermal and package considerations
The DirectFET package is a surface-mount can with a metal top that acts as the drain contact and primary thermal path.