Infineon Technologies IRFR420TRPBF

Overview

IRFR420TRPBF from Infineon is a 500 V, 3.0 Ω R_DS(on) max N-channel enhancement-mode power MOSFET in D-Pak (TO-252) package, rated for 2.4 A continuous drain current at T_C = 25°C and featuring repetitive avalanche rating, fast switching (t_r = 8.6 ns), and 400 mJ single-pulse avalanche energy - used in offline AC-DC flyback and buck converters.

For engineers reviewing the IRFR420TRPBF datasheet, IRFR420TRPBF pinout, IRFR420TRPBF application, or IRFR420TRPBF equivalent, key selection criteria include V_DSS = 500 V, R_DS(on) ≤ 3.0 Ω at V_GS = 10 V, avalanche ruggedness, surface-mount thermal performance (R_θJA = 50 °C/W on PCB mount), and gate charge Q_g = 19 nC for hard-switched SMPS designs.

Technical Context

This MOSFET employs Infineon's third-generation HEXFET® planar silicon process optimized for high-voltage switching with low conduction loss and robust avalanche capability. Its gate threshold voltage (V_GS(th) = 2.0–4.0 V) supports standard 10 V gate drive, and its dynamic parameters - including Q_gd = 13 nC and C_iss = 360 pF - indicate suitability for medium-frequency (<500 kHz) isolated DC-DC topologies.

The device integrates a co-packaged body diode with t_rr = 260–520 ns and peak dv/dt immunity of 3.5 V/ns at 150°C, enabling reliable operation in discontinuous conduction mode (DCM) flyback converters without external snubbing in many cases.

Key Specifications

Pinout & Package

D-Pak (TO-252) surface-mount package with exposed drain tab for thermal and electrical connection; compatible with vapor phase, infrared, and wave soldering per AN-994 footprint guidelines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STP4NK50ZFP and FQP4N50, IRFR420TRPBF delivers superior avalanche ruggedness (400 mJ vs. unspecified/none) and optimized SMT thermal resistance (50 °C/W vs. >62 °C/W), making it preferred for production-grade, space-constrained, high-reliability offline power stages.

Availability

IRFR420TRPBF is available at Aetrix Electronics and suitable for AC-DC flyback converters, industrial relay drivers, HV buck regulators, and offline LED drivers requiring stable component supply and long-term manufacturability.

Supply support for IRFR420TRPBF 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 German semiconductor leader specializing in power management, automotive MCUs, and industrial sensors, with broad portfolio coverage from discrete devices to system-level solutions.

The HEXFET® Power MOSFET product line targets cost-sensitive, high-reliability power conversion applications - emphasizing ruggedness, manufacturability, and thermal efficiency in consumer, industrial, and lighting power supplies.

FAQ

What is the maximum junction temperature and how does it affect reliability?

The IRFR420TRPBF has a rated operating junction temperature range of –55°C to +150°C. At 150°C, its R_DS(on) increases by ~70% versus 25°C, and its body diode V_SD drops to ~1.2 V. Derating curves in Figure 4 and Figure 9 confirm usable current down to 1.5 A at T_C = 100°C, ensuring reliability in sealed enclosures with passive cooling.

Is the body diode suitable for synchronous rectification?

No - the integrated body diode has t_rr = 260–520 ns and Q_rr = 0.7–1.4 µC, which causes significant switching loss and voltage overshoot when used as a synchronous rectifier. It is designed for freewheeling and clamping only; external Schottky or MOSFET synchronous rectifiers are required for high-efficiency designs.

Can IRFR420TRPBF be paralleled for higher current?

Yes - its positive temperature coefficient of R_DS(on) (0.59 V/°C) enables stable current sharing. Layout must ensure matched gate drive impedance and symmetrical source inductance (L_s = 7.5 nH typical); use Kelvin-source connections and individual 10 Ω gate resistors to minimize oscillation risk.

What is the recommended PCB footprint and thermal relief strategy?

Per Infineon Application Note AN-994, use a minimum 1" × 1" (25.4 mm × 25.4 mm) copper pour on the drain pad, with ≥4 thermal vias (0.3 mm diameter, filled or plated) connecting to inner ground/power planes. Avoid solder mask over the drain pad to maximize thermal transfer; maintain ≥0.5 mm clearance from adjacent traces to prevent arcing at 500 V.