Nexperia USA Inc. BUK9Y2R4-40HX

Overview

BUK9Y2R4-40HX from Nexperia is an automotive-qualified N-channel logic-level MOSFET using Trench 9 superjunction technology in LFPAK56 (SOT669) package, rated for 40 V V_DS, 2.4 mΩ R_DS(on) at V_GS = 10 V and T_j = 25 °C, 120 A continuous drain current, and qualified to AEC-Q101 with 175 °C junction rating - deployed in 12 V automotive motor, lamp, and solenoid control.

For engineers reviewing the BUK9Y2R4-40HX datasheet, BUK9Y2R4-40HX pinout, BUK9Y2R4-40HX application, or BUK9Y2R4-40HX equivalent, key selection criteria include R_DS(on) stability over temperature, avalanche ruggedness (81.5 mJ), thermal resistance (0.63 K/W j-mb), gate charge profile (Q_G(tot) = 35.4 nC), and LFPAK56 board-level reliability under thermal cycling.

Technical Context

This MOSFET employs Trench 9 superjunction architecture to achieve reduced cell pitch, enabling lower R_DS(on) and improved SOA/avalanche capability versus standard TrenchMOS. Its tight V_GS(th) range (1.35–2.05 V typ at 25 °C) supports stable paralleling in high-current automotive modules.

The LFPAK56 package integrates copper clip interconnects and gull-wing leads, delivering 0.63 K/W typical thermal resistance from junction to mounting base and eliminating need for x-ray inspection via AOI-compatible solder joints - critical for start-stop micro-hybrid power stages where thermal transients and mechanical stress dominate lifetime failure modes.

Key Specifications

Pinout & Package

LFPAK56 (SOT669) is a 4-terminal surface-mount plastic package with exposed copper mounting base connected to drain, optimized for high-power density and board-level reliability. Gull-wing leads enable visual AOI inspection and superior thermal/mechanical performance vs. QFN.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STL220N4F7AG and NTMFS4C09NT1G, BUK9Y2R4-40HX delivers superior thermal performance (0.63 K/W), tighter V_GS(th) control for paralleling, and documented AEC-Q101 compliance - making it the preferred choice for high-reliability 12 V automotive power switching where junction temperature management and functional safety traceability are mandatory.

Availability

BUK9Y2R4-40HX is available at Aetrix Electronics and suitable for 12 V automotive systems, start-stop micro-hybrid applications, and transmission control modules requiring stable component supply across extended vehicle lifecycles and production ramp phases.

Supply support for BUK9Y2R4-40HX 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 MOSFETs, ESD protection, and logic solutions.

BUK9Y2R4-40HX belongs to Nexperia's LFPAK automotive MOSFET product line, engineered specifically for thermally demanding 12 V power switching in engine, transmission, and body electronics - emphasizing AEC-Q101 compliance, avalanche robustness, and board-level reliability.

FAQ

What is the maximum continuous drain current for BUK9Y2R4-40HX?

The datasheet specifies 120 A continuous drain current at T_mb = 25 °C, validated in application testing. In real-world designs, this value is constrained by PCB copper area, thermal interface materials, ambient temperature, and airflow - not solely by the device itself. Derating curves in Figure 1 show power dissipation drops to 50% at T_mb = 100 °C.

Does BUK9Y2R4-40HX require a gate resistor for safe operation?

A gate resistor is recommended to control dV/dt and prevent oscillation, especially in high-di/dt applications. With 0.72 Ω typical gate resistance and 35.4 nC total gate charge, a 5 Ω external resistor yields ~30 ns rise/fall times under 1 A gate drive - aligning with typical automotive driver capabilities and minimizing EMI while preserving switching efficiency.

How does the LFPAK56 package improve reliability over QFN alternatives?

LFPAK56 uses copper clip bonding and gull-wing leads instead of solder balls or flat leads, resulting in 3× higher thermal cycling endurance and elimination of void-related solder joint failures. Its exposed drain pad provides direct thermal conduction to the PCB, and the lead geometry enables AOI - removing reliance on costly x-ray inspection for process validation in automotive manufacturing.

Can BUK9Y2R4-40HX be used in parallel configurations?

Yes - its tightly distributed V_GS(th) (1.35–2.05 V typ at 25 °C) and matched R_DS(on) temperature coefficient enable stable current sharing without external balancing resistors. Layout symmetry (equal trace length/impedance to each source/gate) remains critical, and derating to ≤80% of total rated current is advised for long-term reliability.