4.8 mOhm at 10 V — conduction loss floor for a 20 A switch
The IRFH7936TRPBF is an Infineon N-channel HEXFET MOSFET rated for 30 V drain-source and 20 A continuous switching current. Its on-resistance of 4.8 mOhm max at Vgs=10 V and Id=20 A sets the conduction loss floor for a power stage — at 20 A the I²R loss is under 2 W, which the 3.1 W package dissipation limit can handle with adequate copper on the drain pad.
Gate charge and drive budget
Total gate charge is 26 nC at Vgs=4.5 V, which is typical for a 20 A-class trench MOSFET. At a 100 kHz switching frequency the gate drive current needed is 2.6 mA average — a standard 1 A gate driver has ample headroom. The ±20 V Vgs rating allows the use of 12 V gate drives without clamping, though the 4.8 mOhm spec is guaranteed at 10 V.
Thermal budget for 150°C junction
The junction temperature range covers -55°C to 150°C, so the part can operate in under-hood automotive or industrial enclosures where ambient hits 85°C. The 3.1 W maximum power dissipation assumes a PCB with adequate copper area on the drain pad; in a 85°C ambient the allowable dissipation drops to about 1.5 W before reaching 150°C TJ.