Infineon Technologies IRFB7746PBF

Overview

IRFB7746PBF from Infineon Technologies (formerly International Rectifier) is a 75V, 59A N-channel enhancement-mode HEXFET® Power MOSFET in TO-220AB package, optimized for high-efficiency switching in motor drives and DC/DC converters. It delivers 9.0 mΩ typical R_DS(on) at V_GS = 10 V, supports 219 A pulsed drain current, and features enhanced body diode dV/dt and dI/dt capability for robust synchronous rectification in half-bridge topologies.

For engineers reviewing the IRFB7746PBF datasheet, IRFB7746PBF pinout, IRFB7746PBF application, or IRFB7746PBF equivalent, key selection criteria include its 75 V V_DSS, 9.0 mΩ R_DS(on), 55 nC total gate charge, avalanche-rated 111 mJ single-pulse energy, and TO-220AB thermal resistance of 1.52 °C/W junction-to-case - critical for brushed/BLDC motor control and resonant-mode power supply designs.

Technical Context

This N-channel MOSFET employs planar silicon process technology with optimized cell layout to achieve low on-resistance while maintaining high avalanche ruggedness. Its gate threshold voltage (2.1–3.7 V) enables reliable turn-on with standard 5 V or 10 V logic-level drivers, and its fully characterized C_iss (3049 pF), C_oss (255 pF), and Q_gd (16 nC) support precise switching loss calculation in hard-switched and ZVS topologies.

The device integrates a fast, soft-recovery body diode with t_rr = 28 ns (T_J = 25°C), Q_rr = 30 nC, and dv/dt capability up to 8.0 V/ns at T_J = 175°C - enabling stable OR-ing and synchronous rectifier operation without external Schottky diodes in 48 V battery-powered systems.

Key Specifications

Pinout & Package

IRFB7746PBF uses the industry-standard TO-220AB package with isolated tab (drain-connected), offering mechanical robustness and proven thermal performance in high-power applications. The three-terminal configuration supports straightforward PCB layout and heatsink integration.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar N-channel power MOSFET applications.

Compared with STP75NF75 and IXTH75N10L2, IRFB7746PBF offers the optimal balance of low gate charge (55 nC), tight R_DS(on) tolerance (9.0–10.6 mΩ), and TO-220 thermal resistance (1.52 °C/W), making it preferred for space-constrained, medium-frequency motor drives and DC/DC converters requiring rapid design reuse.

Availability

IRFB7746PBF is available at Aetrix Electronics and suitable for brushed motor drives, BLDC inverters, and synchronous rectifier circuits requiring stable component supply, long-term lifecycle support, and traceable sourcing for industrial and embedded OEM programs.

Supply support for IRFB7746PBF 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

Infineon Technologies is a global semiconductor leader specializing in power management, sensor, and automotive ICs, with deep expertise in silicon-based power devices and system-level solutions.

This device belongs to Infineon's StrongIRFET™ family of high-ruggedness HEXFET® MOSFETs, engineered specifically for demanding industrial motor control, uninterruptible power supplies, and high-efficiency DC/DC conversion where avalanche reliability and body diode performance are critical.

FAQ

Is IRFB7746PBF suitable for 48 V battery-powered BLDC motor controllers?

Yes. Its 75 V V_DSS provides 50 % overvoltage margin above 48 V nominal bus, and its 59 A continuous current rating supports peak phase currents up to 219 A in short bursts. The 28 ns reverse recovery time and 8.0 V/ns dv/dt rating prevent shoot-through during high-di/dt commutation, making it ideal for compact, high-efficiency BLDC inverters.

What is the maximum recommended gate resistor for reliable switching?

A 2.7 Ω gate resistor is specified in the datasheet for switching characterization (td(off) = 33 ns, tf = 30 ns). For 100 kHz operation with minimal overshoot, use 2.2–3.3 Ω in series with the gate driver output. Lower values increase peak gate current demand; higher values slow switching and raise losses - always verify with actual layout parasitics and driver capability.

Does IRFB7746PBF require a heatsink in TO-220 mounting?

Yes. At 59 A continuous current and 9.0 mΩ R_DS(on), conduction loss exceeds 31 W. With R_θJC = 1.52 °C/W and typical R_θCS = 0.5 °C/W, a heatsink with ≤1.0 °C/W total thermal resistance to ambient is required to maintain T_J < 150°C at 25°C ambient - verified via thermal simulation or IR thermography under real load.

Can IRFB7746PBF replace IRFZ44N in existing designs?

Yes, with qualification. Both are TO-220 N-channel MOSFETs, but IRFB7746PBF offers 75 V V_DSS (vs. 55 V), 9.0 mΩ R_DS(on) (vs. 28 mΩ), and superior avalanche energy (111 mJ vs. 55 mJ). Gate threshold remains compatible (2.1–3.7 V), but higher transconductance (132 S) demands verification of gate drive stability and shoot-through immunity in bridge layouts.