75 V StrongIRFET in a TO-220AB — what it carries
The Infineon IRFB7740PBF is an N-channel MOSFET from the StrongIRFET™ series, rated for 75 V drain-to-source and 87 A continuous drain current at a 25 °C case temperature. Packaged in a through-hole TO-220AB, it delivers 7.3 mOhm maximum on-resistance when driven with 10 V on the gate. The junction temperature range of -55 °C to 175 °C suits it for industrial motor drives, battery-management systems, and power-conversion stages where the board sees thermal cycling.
Rds(on) and gate charge — the switching trade-off
At 7.3 mOhm with a 10 V gate drive, conduction losses stay low even at 52 A load current. The 122 nC total gate charge at 10 V is moderate — a standard gate-driver IC can switch it without excessive drive current, but the 4650 pF input capacitance at 25 V drain means the driver should source a few amps for fast edges in hard-switched converters. The drive voltage window of 6 V to 10 V lets you trade off Rds(on) against gate-drive complexity: 10 V gives the lowest on-resistance; 6 V still works but at higher resistance.
Thermal derating and mounting
The 143 W maximum power dissipation is specified at the case temperature — that number assumes a heatsink with good thermal interface. In a real enclosure, derate the continuous current from 87 A based on the junction-to-case thermal resistance and ambient conditions. The TO-220AB package fits standard clip or screw-mount heatsinks; the through-hole leads suit wave-solder assembly on FR4 or metal-core boards.
Lifecycle and sourcing
The IRFB7740PBF carries an Active lifecycle status. It is ROHS3 compliant. The StrongIRFET™ series is a current-production family.