Infineon Technologies IRLL3303

Overview

IRLL3303 from International Rectifier is a logic-level N-channel enhancement-mode Power MOSFET in SOT-223 package, rated for 30V V_DSS, 4.6A continuous drain current at 25°C, and 0.031Ω R_DS(on) at V_GS = 10V. It delivers fast switching (t_r = 22ns, t_f = 28ns), high dv/dt immunity (1.3 V/ns), and robust unclamped inductive avalanche capability (140 mJ), making it suitable for DC-DC converters, load switches, and motor drive half-bridges.

For engineers reviewing the IRLL3303 datasheet, IRLL3303 pinout, IRLL3303 application, or IRLL3303 equivalent, key selection criteria include logic-level gate drive compatibility (V_GS(th) = 1.0–2.5V), thermal resistance (R_θJA = 93°C/W on FR-4), body diode recovery performance (t_rr = 65–98ns), and SO-223 package thermal derating (8.3 mW/°C).

Technical Context

This HEXFET device uses fifth-generation silicon processing to achieve ultra-low on-resistance per die area while maintaining ruggedness against repetitive avalanche stress (E_AR = 0.10 mJ) and high dv/dt transients. Its gate charge profile (Q_g = 34 nC typ.) supports efficient PWM operation at frequencies up to several hundred kHz.

The integrated body diode exhibits low forward voltage (V_SD = 1.3V at I_S = 4.6A) and controlled reverse recovery (Q_rr = 160–240 nC), enabling reliable synchronous rectification and freewheeling in buck and H-bridge topologies without external Schottky supplementation.

Key Specifications

Pinout & Package

SOT-223 (TO-261AA) surface-mount package with exposed drain tab for enhanced heatsinking. Thermal pad connects internally to Drain terminal; requires solder mask defined copper pour for optimal PCB thermal transfer.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DMN3025LSD-13 and SI2303DS-T1-GE3, IRLL3303 offers superior thermal performance (1.0W vs. ≤0.5W), balanced gate charge for medium-frequency PWM, and proven avalanche ruggedness-making it the preferred choice for industrial-grade 4–5A load switching where reliability and thermal margin are prioritized.

Availability

IRLL3303 is available at Aetrix Electronics and suitable for DC-DC converters, smart load switches, H-bridge motor drivers, and LED constant-current dimmers requiring stable component supply and long-term industrial availability.

Supply support for IRLL3303 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 semiconductor design, specializing in high-efficiency MOSFETs, IGBTs, and driver ICs for industrial, automotive, and computing applications.

The HEXFET® product line was engineered for high-power-density, high-reliability switching in thermally constrained environments-emphasizing low R_DS(on), fast switching, and rugged avalanche performance across SMT packages like SOT-223.

FAQ

Is IRLL3303 suitable for 3.3V microcontroller gate drive?

Yes. With V_GS(th) max of 2.5V and R_DS(on) = 0.045Ω at V_GS = 4.5V, IRLL3303 achieves full enhancement using 3.3V logic when paired with a gate driver buffer or low-impedance GPIO. At 3.3V, R_DS(on) rises to ~0.07Ω, limiting continuous current to ~3A with adequate heatsinking.

What is the maximum PCB copper area needed to achieve 2.1W power dissipation?

To reach the 2.1W rating, the datasheet specifies mounting on a 1-inch square (25.4 mm × 25.4 mm) copper pad with 2-oz thickness and no thermal vias. Achieving this requires full-surface copper fill under the SOT-223 drain tab, isolated from other nets, and free of solder mask over the thermal pad.

Can IRLL3303 replace IRFL3303 in existing designs?

Yes-IRLL3303 and IRFL3303 share identical electrical specs, pinout, and SOT-223 package. The "L" suffix denotes lead-free (PbF) construction, while "F" indicates standard leaded finish. Both meet the same JEDEC moisture sensitivity level (MSL3) and thermal profiles.

Does the body diode support synchronous rectification in buck converters?

It can be used for asynchronous operation, but its Q_rr (160–240 nC) and t_rr (65–98 ns) are higher than dedicated Schottky diodes. For synchronous rectification above 100 kHz, an external low-Q_rr MOSFET is recommended; IRLL3303's body diode is best suited for lower-frequency freewheeling or fault protection.