Infineon Technologies IRFU1205

Overview

IRFU1205 from International Rectifier is a 55V, 44A N-channel enhancement-mode HEXFET® Power MOSFET in TO-251AA (I-PAK) through-hole package, featuring 27 mΩ R_DS(on) at V_GS = 10 V, fully avalanche-rated operation, and fast switching with 65 nC total gate charge. It serves as a high-efficiency main or synchronous rectifier switch in DC-DC converters, motor drives, and power supplies.

For engineers reviewing the IRFU1205 datasheet, IRFU1205 pinout, IRFU1205 application, or IRFU1205 equivalent, key selection criteria include its 55 V V_DS, 27 mΩ on-resistance at 10 V drive, 160 A pulsed drain rating, and rugged unclamped inductive switching capability up to 210 mJ single-pulse avalanche energy.

Technical Context

This fifth-generation HEXFET uses advanced silicon processing to minimize R_DS(on) per die area while maintaining robust safe operating area (SOA) and thermal stability. Its body diode exhibits 1.3 V forward voltage at 22 A and 65–98 ns reverse recovery time under 100 A/µs di/dt.

The device operates across –55°C to +175°C junction temperature, supports ±20 V gate drive, and delivers linear derating of 0.71 W/°C above 25°C case temperature. Thermal resistance is 1.4 °C/W junction-to-case and 110 °C/W junction-to-ambient (free air).

Key Specifications

Pinout & Package

IRFU1205 is housed in TO-251AA (I-PAK), a through-hole package with isolated tab (Drain-connected) and three leads: Gate (Lead 1), Drain (Lead 2 & 4), Source (Lead 3). The metal tab is electrically connected to Drain and provides mechanical mounting and thermal path.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar power switching applications.

Compared with STP55NF06L and IRFZ44NPBF, IRFU1205 offers superior mechanical reliability via through-hole mounting, lower thermal resistance than TO-220 in constrained airflow, and optimized gate charge for 5–15 V drive systems-making it ideal for ruggedized industrial power modules.

Availability

IRFU1205 is available at Aetrix Electronics and suitable for DC-DC converters, motor controllers, and LED drivers requiring stable component supply, long-term manufacturability, and consistent parametric performance across production lots.

Supply support for IRFU1205 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

International Rectifier (now part of Infineon Technologies) was a pioneer in power MOSFET innovation, specializing in high-efficiency silicon-based power semiconductors for industrial, automotive, and computing markets.

IRFU1205 belongs to the HEXFET® fifth-generation power MOSFET product line, engineered for high-current, medium-voltage switching in space-constrained and thermally demanding applications such as power supplies and motor controls.

FAQ

Is IRFU1205 suitable for 3.3 V microcontroller gate drive?

No. IRFU1205 has a gate threshold voltage range of 2.0–4.0 V and requires ≥10 V for full enhancement to achieve its rated 27 mΩ R_DS(on). At 3.3 V, R_DS(on) exceeds 0.15 Ω, increasing conduction loss fivefold. A logic-level MOSFET like STP55NF06L is required for direct 3.3 V drive.

Can IRFU1205 replace IRFZ44N in an existing TO-220 PCB layout?

No. IRFU1205 uses TO-251AA (I-PAK) with three leads and a tab, while IRFZ44N uses TO-220 with three leads and a different pinout (G-D-S vs. G-D-S but non-interchangeable lead spacing and mounting hole pattern). Mechanical and solder mask footprints are incompatible without PCB redesign.

What is the maximum continuous current when mounted on a 2-layer 1 oz copper PCB without heatsink?

At T_A = 50°C ambient, the junction-to-ambient thermal resistance is ~110 °C/W. With T_J(max) = 175°C, allowable ΔT = 125°C. Max power = 125°C ÷ 110 °C/W ≈ 1.14 W. Using P = I²R, I_max = √(1.14 W ÷ 0.027 Ω) ≈ 6.5 A continuous.

Does IRFU1205 have built-in ESD protection on the gate?

No. Like most discrete power MOSFETs, IRFU1205 lacks integrated gate ESD protection. Its gate oxide is susceptible to damage from static discharge exceeding ±20 V. Recommended handling includes grounded wrist straps, conductive foam storage, and series gate resistors (≥10 Ω) in circuit to limit transient current.