Infineon Technologies IRF6618

Overview

IRF6618 from Infineon Technologies (formerly International Rectifier) is a 30V N-channel Power MOSFET in DirectFET MT package, optimized for synchronous buck CPU core DC-DC converters. It delivers 2.2 mΩ R_DS(on) at V_GS = 10 V, 43 nC total gate charge, and 1.4 °C/W junction-to-case thermal resistance, enabling high-efficiency power delivery to modern high-frequency processors.

For engineers reviewing the IRF6618 datasheet, IRF6618 pinout, IRF6618 application, or IRF6618 equivalent, key selection criteria include C_dv/dt immunity for robust synchronous FET operation, ultra-low package inductance for reduced switching loss, dual-sided cooling compatibility, and SO-8 footprint compatibility with sub-0.7 mm profile.

Technical Context

The IRF6618 employs HEXFET silicon with DirectFET MT packaging to minimize conduction and switching losses simultaneously. Its 3.4 mΩ R_DS(on) at 4.5 V enables efficient operation in 5 V gate-drive systems, while its 570 pF Crss and 15 nC Q_gd support fast, controlled turn-off under high dV/dt conditions.

Designed specifically for high-frequency synchronous buck topologies, it features enhanced C_dv/dt-induced turn-on immunity and low reverse recovery charge (Q_rr = 46–69 nC), reducing shoot-through risk and body diode losses during dead-time transitions.

Key Specifications

Pinout & Package

IRF6618 uses the DirectFET MT (Medium Size Can, T-Designation) package - a top-side source-connected, double-sided cooling metal-can structure with SO-8 compatible footprint and 0.7 mm maximum height. The package exposes drain on the bottom thermal pad and source on the top metal can, with gate on a dedicated side terminal.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-efficiency synchronous buck FET applications.

Compared with IRF6618, IRF6622 trades higher switching loss for lower conduction loss, while SiR626DP sacrifices thermal performance and C_dv/dt robustness for standard SO-8 assembly - making IRF6618 optimal where dual-sided cooling and synchronous FET reliability are critical.

Availability

IRF6618 is available at Aetrix Electronics and suitable for server CPU VRMs, laptop processor power stages, and AI accelerator board power delivery requiring stable component supply and long-term industrial lifecycle support.

Supply support for IRF6618 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, and industrial control ICs and discrete devices.

The IRF6618 belongs to Infineon's DirectFET® Power MOSFET product line, engineered to replace traditional TO-220 and SO-8 packages in high-density, high-efficiency DC-DC conversion for computing and communications infrastructure.

FAQ

What is the recommended gate resistor value for IRF6618 in a 500 kHz synchronous buck converter?

A 2.2 Ω to 4.7 Ω gate resistor is recommended to balance switching speed and ringing suppression. With 43 nC Q_g and typical 12 V gate drive, this yields ~10–20 ns rise/fall times, minimizing overlap loss while containing EMI from 570 pF Crss and low-inductance layout.

Can IRF6618 be used as a high-side switch in a floating-gate configuration?

No - IRF6618 is optimized as a low-side or synchronous rectifier FET. Its gate threshold (1.35–2.35 V) and lack of integrated level-shifting make it unsuitable for high-side bootstrap operation without external gate bias circuitry and careful dV/dt management.

Does IRF6618 require special PCB layout considerations beyond standard SO-8 guidelines?

Yes - the DirectFET MT package requires dedicated thermal vias under the bottom drain pad (≥8×0.3 mm vias to inner ground plane) and top-side copper pour on the source can. Stencil design must follow AN-1035 for 0.12 mm thickness and 1:1 aperture ratio to ensure void-free solder joint formation.

How does IRF6618's avalanche rating compare to standard SO-8 MOSFETs?

IRF6618 is rated for 210 mJ single-pulse avalanche energy at 24 A, significantly higher than most SO-8 MOSFETs (<50 mJ). This stems from its robust silicon die and low R_θJC, allowing safe operation during unclamped inductive transients common in VRM fault conditions.