Nexperia USA Inc. BUK9M4R3-40HX

Overview

BUK9M4R3-40HX from Nexperia is an AEC-Q101 qualified N-channel logic-level MOSFET in LFPAK33 (SOT1210) package, rated for 40 V V_DS, 4.3 mΩ R_DS(on) at V_GS = 10 V and T_j = 25 °C, and 95 A continuous drain current at T_mb = 25 °C. It serves as a high-efficiency power switch in 12 V automotive subsystems including body control modules and LED lighting drivers.

For engineers reviewing the BUK9M4R3-40HX datasheet, BUK9M4R3-40HX pinout, BUK9M4R3-40HX application, or BUK9M4R3-40HX equivalent, key selection criteria include its Trench 9 superjunction architecture for low conduction loss, gull-wing lead form for AOI compatibility, repetitive avalanche rating, and junction-to-mounting-base thermal resistance of 1.48 K/W.

Technical Context

This MOSFET employs Trench 9 TrenchMOS technology to achieve high power density and low R_DS(on) with excellent switching performance: Q_GD = 3.3–6.6 nC at V_GS = 4.5 V and Q_G(tot) = 14–20 nC at V_GS = 10 V. Its gate threshold voltage ranges from 0.7 V (min at T_j = 175 °C) to 2.15 V (max at T_j = 25 °C), enabling robust logic-level drive.

The LFPAK33 package integrates a copper clip for low-inductance drain connection and high-current source terminals (Pins 1–3), with the mounting base electrically connected to drain. Thermal design leverages direct die-to-mounting-base path (R_th(j-mb) = 1.48 K/W typ), supporting high-power operation in constrained automotive PCB layouts.

Key Specifications

Pinout & Package

LFPAK33 (SOT1210) is a surface-mount, single-ended package with gull-wing leads and an exposed copper mounting base electrically tied to the drain. Its compact 3.2 mm × 2.4 mm footprint and 0.65 mm pitch support high-density automotive PCB layouts and automated optical inspection (AOI).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar N-channel 40 V automotive MOSFET applications.

Compared with BUK9M4R3-40HX, BSC014N04LS6 offers marginally lower conduction loss but inferior thermal performance and reduced high-temperature reliability, while NTMFS4C09NT1G trades 0.5 mΩ higher R_DS(on) for lower unit cost but removes built-in avalanche protection-making BUK9M4R3-40HX optimal for thermally demanding, safety-critical 12 V automotive switches.

Availability

BUK9M4R3-40HX is available at Aetrix Electronics and suitable for automotive body electronics, LED lighting systems, and 12 V DC-DC converters requiring stable component supply across extended product lifecycles.

Supply support for BUK9M4R3-40HX 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

Nexperia is a global semiconductor expert focused on high-volume, high-reliability discrete and logic devices, with leadership in automotive-qualified MOSFETs and ESD protection.

BUK9M4R3-40HX belongs to Nexperia's LFPAK33 automotive logic-level MOSFET family, engineered specifically for space-constrained, thermally aggressive 12 V vehicle subsystems where AEC-Q101 compliance and robust avalanche behavior are mandatory.

FAQ

Is BUK9M4R3-40HX pin-compatible with earlier BUK9M4R3-40H?

Yes-BUK9M4R3-40HX is a qualified variant of BUK9M4R3-40H with identical LFPAK33 (SOT1210) pinout, electrical specifications, and thermal characteristics. The 'X' suffix denotes enhanced traceability and updated manufacturing controls per Nexperia's 2025 quality roadmap, with no functional or mechanical changes.

What is the maximum recommended gate resistor for 100 kHz PWM switching?

A gate resistor of 5 Ω is validated for reliable 100 kHz operation with V_GS = 4.5 V drive, achieving t_f = 9.3 ns and minimizing shoot-through risk. Higher values (>10 Ω) increase switching losses and may cause incomplete turn-on at elevated temperatures due to V_GS(th) drift.

Can BUK9M4R3-40HX be used in high-side configuration with 12 V supply?

Yes-it supports high-side switching when paired with a gate driver capable of providing ≥10 V gate-to-source voltage relative to the source node. Its 20 V V_GS rating and 0.7 V minimum V_GS(th) ensure robust turn-on even with driver supply droop or temperature variation.

Does the mounting base require thermal vias or solder mask defined pads?

Yes-the mounting base must be soldered to a large, multi-layer PCB copper pour with ≥6 thermal vias (0.3 mm diameter, 0.65 mm pitch) connecting to internal ground planes. Use solder mask defined pads per Nexperia's SOT1210 footprint (Fig. 19) to ensure uniform solder joint formation and optimal R_th(j-mb) performance.