Skip to main content
Log in
Infineon Technologies IRF40B207

IRF40B207 MOSFET N-CH 40V 95A TO-220AB, 4.5 mOhm Rds(on)

MPNIRF40B207
End of Life

Infineon IRF40B207, HEXFET StrongIRFET series, N-channel MOSFET, 40 V Vdss, 95 A Id, 4.5 mOhm Rds(on) at 10 V, 68 nC Qg, TO-220AB, -55 to 175 °C.

$1.27Ref. price · indicative, final on quote
Infineon Technologies IRF40B207 datasheet (PDF)
PackagingTO-220-3
RoHSROHS3 Compliant
SeriesHEXFET®, StrongIRFET™
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

IRF40B207 specifications
ParameterValue
SeriesHEXFET®, StrongIRFET™
FET typeN-Channel
MountingThrough Hole
Drain to source voltage40 V
Drive voltage (Max rds on, min rds on)6V, 10V
Current - continuous drain (Id) @ 25°C95A (Tc)
Power dissipation83W (Tc)
Operating temperature-55°C ~ 175°C (TJ)
PackageTube
Vgs±20V
TechnologyMOSFET (Metal Oxide)
CaseTO-220-3
Vgs(th) (Max) @ id3.9V @ 50µA
Rds on (Max) @ id, vgs4.5mOhm @ 57A, 10V
Gate charge (Qg) (Max) @ vgs68 nC @ 10 V
Input capacitance (Ciss) (Max) @ vds2110 pF @ 25 V

Product details

Total gate charge is 68 nC at 10 V. The drive voltage range is specified from 6 V (minimum for rated Rds(on)) to 10 V (for the full 4.5 mOhm). A 12 V gate drive is fine within the ±20 V Vgs max, but the 10 V figure is the one to design to for the datasheet Rds(on) number.

175 °C junction — where this part lives

That 175 °C ceiling is a step above the common 150 °C limit — it suits under-hood automotive, engine-bay, or industrial enclosures where ambient air hits 85 °C and the heatsink sees 100 °C. The 83 W power dissipation at case temperature is the thermal budget; at 50 A continuous with 4.5 mOhm, conduction loss is about 11.25 W, leaving headroom for switching losses before the junction reaches 175 °C.

This is a low-voltage, high-current switch. The 40 V Vdss ceiling means it belongs in 12 V, 24 V, or 36 V rails — not a 48 V telecom bus (which needs 60 V or 80 V rated parts). Typical applications include brushed and brushless DC motor drivers, secondary-side synchronous rectification in 12 V output power supplies, battery-management load switches, and low-voltage inverter stages.

Frequently asked questions

What is the exact on-resistance (Rds(on)) of the IRF40B207 at 10V gate drive?

The maximum Rds(on) is 4.5 mOhm at 57 A drain current and 10 V gate-to-source voltage. This is the figure to use for worst-case conduction-loss calculations at 25 °C junction; at elevated temperature the on-resistance increases per the normalised curve in the datasheet.

Can IRF40B207 be used as a replacement for the IRFZ44N in a 12V motor driver?

The IRF40B207 has a lower Rds(on) (4.5 mOhm vs the IRFZ44N's typical 17.5 mOhm) and a higher 95 A continuous rating, so it will run cooler at the same load current. The 40 V Vdss matches the IRFZ44N's 55 V rating for a 12 V rail. The TO-220AB package is pin-compatible. It is a viable upgrade, but confirm the gate-drive voltage — the IRF40B207 is specified at 10 V for full Rds(on), while the IRFZ44N is often driven at 10 V as well.

What is the maximum drain current (Id) of IRF40B207 at 25°C case temperature?

The continuous drain current is rated at 95 A when the case temperature is held at 25 °C. This is a package-limited rating at the TO-220AB's thermal capability; at elevated case temperatures the current must be derated.

Does the IRF40B207 require a heatsink for 50A continuous operation?

At 50 A with 4.5 mOhm Rds(on), conduction loss is about 11.25 W. The maximum power dissipation is 83 W at case temperature, so 11.25 W is within the device's capability — but without a heatsink the junction will rise well above 25 °C. A modest heatsink (thermal resistance around 5-10 °C/W) is recommended to keep the junction below 125 °C in a 25 °C ambient.