Infineon Technologies IRLR8743TRLPBF

Overview

IRLR8743TRLPBF from Infineon Technologies is an N-channel enhancement-mode HEXFET Power MOSFET in D-Pak (TO-252) package, rated for 30V V_DS, 3.1 mΩ R_DS(on) at V_GS = 4.5V, 39 nC total gate charge, and 640 A pulsed drain current - optimized for high-frequency synchronous buck converters in CPU power delivery.

For engineers reviewing the IRLR8743TRLPBF datasheet, IRLR8743TRLPBF pinout, IRLR8743TRLPBF application, or IRLR8743TRLPBF equivalent, key selection criteria include low R_DS(on) at 4.5V drive, ultra-low gate impedance (0.85–1.5 Ω), fully characterized avalanche capability (13.5 mJ E_AS), and body diode performance (t_rr = 18–27 ns, Q_rr = 32–48 nC) for synchronous rectification in telecom DC-DC systems.

Technical Context

This MOSFET employs a trench-gate silicon process to achieve sub-3.5 mΩ on-resistance with 4.5V gate drive, enabling efficient operation in 3.3V/5V logic-level control environments. Its gate charge profile (Q_gs1 = 10 nC, Q_gd = 13 nC, Q_sw = 17 nC) supports fast switching with minimal C_dv/dt turn-on risk when used as a synchronous FET in buck topologies.

The device integrates a robust intrinsic body diode with low forward voltage (V_SD ≤ 1.0 V at 20A) and tightly specified reverse recovery (Q_rr, t_rr) - critical for minimizing shoot-through and cross-conduction losses in high-dV/dt node applications like multiphase VRMs.

Key Specifications

Pinout & Package

IRLR8743TRLPBF is housed in a surface-mount D-Pak (TO-252) package with exposed drain pad for thermal and electrical performance. The three-terminal configuration supports high-current, low-inductance PCB layout in power stage designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IRL8743PBF, IRLR8743TRLPBF adds tape-and-reel packaging for SMT automation, while SiR874DP-T1-GE3 offers lower gate charge at the cost of 0.7 mΩ higher on-resistance - making it more suitable for very high-frequency, low-duty-cycle applications where switching loss outweighs conduction loss.

Availability

IRLR8743TRLPBF is available at Aetrix Electronics and suitable for server VRMs, telecom DC-DC converters, industrial PLC power supplies, and high-density POL modules requiring stable component supply and long-term manufacturing continuity.

Supply support for IRLR8743TRLPBF 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 manufacturer specializing in power management, automotive, and industrial control ICs and discrete devices.

This part belongs to Infineon's HEXFET® logic-level MOSFET product line, engineered specifically for high-efficiency, high-frequency DC-DC conversion in computing and communications infrastructure where low gate-threshold operation and robust avalanche performance are mandatory.

FAQ

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

The IRLR8743TRLPBF supports 68 A continuous drain current at T_C = 100°C with V_GS = 10 V, as specified in the Absolute Maximum Ratings table. Derating is linear at 1.6 W/°C above 100°C case temperature, and thermal design must account for R_θJC = 1.11 °C/W to maintain junction temperature below 175°C.

Does this MOSFET require a gate resistor for stability in 500 kHz buck operation?

Yes - a 2.2–4.7 Ω series gate resistor is recommended to dampen ringing caused by PCB trace inductance interacting with C_iss (4880 pF) and gate driver output impedance. This prevents false turn-on from dV/dt coupling and ensures clean 20–35 ns rise/fall times per the datasheet switching characterization.

Can IRLR8743TRLPBF replace IRLU8743PbF in a PTH design?

No - IRLU8743PbF uses I-Pak (TO-251) through-hole packaging, while IRLR8743TRLPBF is D-Pak (TO-252) surface-mount. Footprint, thermal pad layout, and reflow profile differ significantly; direct replacement requires PCB redesign and validation of solder joint reliability under thermal cycling.

Is the body diode suitable for reverse recovery in synchronous rectification?

Yes - the body diode is fully characterized with t_rr = 18–27 ns and Q_rr = 32–48 nC at I_F = 20 A, V_DD = 15 V, and di/dt = 300 A/µs. These values enable reliable synchronous rectification in 300–1000 kHz converters when paired with appropriate dead-time control to avoid shoot-through.