650V, 20A N-channel in TO-220 — the switching loss trade-off
The STP26N65DM2 is a 650 V, 20 A N-channel MOSFET from STMicroelectronics' MDmesh™ DM2 series, housed in a through-hole TO-220 package. It is designed for hard-switching topologies where a balance between on-resistance and gate charge matters for efficiency.
Rds(on) is specified at 190 mOhm maximum at 10 A and 10 V drive — this is the conduction loss figure for a 20 A device at full load. At 20 A the junction-to-ambient thermal budget must absorb I²R losses, and the 170 W maximum power dissipation at the case (Tc) gives the thermal design target. Total gate charge is 35.5 nC at 10 Vgs — this sets the driver current needed for a given switching frequency. A 35.5 nC gate charge at 100 kHz requires a 3.55 mA average gate drive current, well within a standard gate driver's capability.
Gate drive thresholds and safe operating range
The ±25 V maximum gate-source rating gives margin for ringing on the gate node in hard-switching bridges. The TO-220 package with a metal tab allows heat sinking to a chassis or heatsink for high-power dissipation.