Infineon Technologies IRFS4321TRRPBF

Overview

IRFS4321TRRPBF from Infineon Technologies (formerly International Rectifier) is an N-channel enhancement-mode HEXFET Power MOSFET in D2Pak (TO-263) package, designed for high-current, hard-switched power conversion stages. It delivers 150 V V_DSS, 12 mΩ typical R_DS(on) at V_GS = 10 V, 85 A continuous drain current at T_C = 25°C, and features fully characterized avalanche SOA - used in synchronous rectification of high-frequency SMPS and UPS output stages.

For engineers reviewing the IRFS4321TRRPBF datasheet, IRFS4321TRRPBF pinout, IRFS4321TRRPBF application, or IRFS4321TRRPBF equivalent, key selection criteria include its 0.43°C/W junction-to-case thermal resistance, 71 nC total gate charge, 130 S forward transconductance, 89–130 ns diode reverse recovery time, and robust 30 V gate rating for drive margin in industrial motor control and DC-DC converter designs.

Technical Context

This MOSFET employs planar silicon process with optimized cell pitch and trench-assisted body diode design to achieve low R_DS(on) while maintaining fast, soft-recovery intrinsic diode behavior. Its gate threshold voltage (3.0–5.0 V) and 0.8 Ω internal gate resistance support stable PWM switching up to 500 kHz in resonant and phase-shifted topologies.

The device's avalanche energy rating (120 mJ single-pulse, thermally limited) and SOA curves are validated across temperature cycles, enabling reliable unclamped inductive switching in motor drives and UPS H-bridges without external snubbers - critical where di/dt exceeds 100 A/μs and V_DS re-applies rapidly after body diode conduction.

Key Specifications

Pinout & Package

IRFS4321TRRPBF uses a surface-mount D2Pak (TO-263) package with three terminals: Gate (G), Drain (D), and Source (S). The exposed drain pad on the bottom provides low-inductance, high-current path and primary thermal conduction to PCB copper.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STP110N15F7 and IXFH50N15X3, IRFS4321TRRPBF offers optimal balance of low R_DS(on), moderate Q_g, and superior thermal performance in surface-mount form factor - making it ideal for compact, air-cooled 500–1000 W industrial power supplies where PCB real estate and thermal management are constrained.

Availability

IRFS4321TRRPBF is available at Aetrix Electronics and suitable for motion control systems, uninterruptible power supplies, and high-frequency hard-switched DC-DC converters requiring stable component supply and long-term industrial lifecycle support.

Supply support for IRFS4321TRRPBF 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 headquartered in Munich, Germany, specializing in power management, automotive microcontrollers, and industrial sensors - with over 30 years of MOSFET innovation.

This device belongs to Infineon's legacy HEXFET® family, engineered specifically for high-efficiency, high-reliability power conversion in industrial motor drives, UPS, and telecom infrastructure - emphasizing rugged avalanche capability and low-loss switching.

FAQ

What is the maximum continuous drain current for IRFS4321TRRPBF at 100°C case temperature?

The datasheet specifies 60 A continuous drain current at T_C = 100°C with V_GS = 10 V. This reflects thermal derating due to reduced channel mobility and increased R_DS(on); actual usable current depends on heatsink thermal resistance and ambient airflow - e.g., with 1.0°C/W heatsink and 40°C ambient, junction temperature remains below 150°C at 60 A.

Does IRFS4321TRRPBF have a specified gate threshold voltage range?

Yes - V_GS(th) is guaranteed between 3.0 V and 5.0 V at I_D = 250 μA and T_J = 25°C. The typical value is ~4.0 V, and it decreases linearly with temperature (−15 mV/°C), reaching ~2.5 V at 175°C - critical for ensuring turn-on margin in high-temperature motor control environments.

Can IRFS4321TRRPBF be used in avalanche mode repeatedly?

No - the datasheet explicitly states "Repetitive avalanche is not recommended." While single-pulse avalanche energy is characterized (120 mJ), repetitive operation risks cumulative thermal stress and die attach fatigue. For circuits requiring frequent inductive energy absorption, external clamping or alternative topologies (e.g., active clamp) must be used.

What is the body diode forward voltage and how does it affect synchronous rectification?

V_SD is rated at ≤1.3 V at I_S = 50 A and T_J = 25°C. In synchronous rectification, this forward drop directly determines conduction loss during freewheeling - 1.3 V × 50 A = 65 W dissipation if unmanaged. However, its fast, soft recovery (t_rr = 89–130 ns) minimizes switching loss and EMI compared to standard diodes, enabling efficient high-frequency operation.