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Home > Products > Discrete Semiconductor Products > Transistors > FETs, MOSFETs > FETs, MOSFETs

Nexperia USA Inc. BUK9Y2R8-40HX

Name: BUK9Y2R8-40HX
Brand: Nexperia USA Inc.
SKU: BUK9Y2R8-40HX
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BUK9Y2R8-40HX

Manufacturer:: Nexperia USA Inc.

Category:: FETs, MOSFETs

Package:: -

Datasheet:: BUK9Y2R8-40HX.pdf

Description:: BUK9Y2R8-40H/SOT669/LFPAK

Quantity:: RFQ Add To RFQ list

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Inventory:6,425

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Product details

Overview

BUK9Y2R8-40HX from Nexperia is an AEC-Q101 qualified N-channel logic-level MOSFET designed for high-current automotive power switching. It delivers 40 V V_DS, 2.8 mΩ R_DS(on) at V_GS = 10 V and T_j = 25 °C, 120 A continuous drain current (T_mb = 25 °C), and operates up to 175 °C junction temperature - deployed in start-stop micro-hybrid systems, transmission control, and 12 V motor/solenoid drivers.

For engineers reviewing the BUK9Y2R8-40HX datasheet, BUK9Y2R8-40HX pinout, BUK9Y2R8-40HX application, or BUK9Y2R8-40HX equivalent, key selection criteria include its LFPAK56 package thermal performance (R_th(j-mb) = 0.77 K/W), tight V_GS(th) distribution (1.35–2.05 V), and avalanche ruggedness (50 mJ unclamped) in thermally demanding automotive environments.

Technical Context

This MOSFET employs Nexperia's Trench 9 Superjunction technology, enabling reduced cell pitch for higher power density and lower R_DS(on) within the LFPAK56 footprint. Its gate threshold voltage is tightly distributed (1.35–2.05 V at 25 °C) to support reliable parallel operation without current imbalance.

The LFPAK56 package integrates a copper clip for low-inductance, high-current conduction and gull-wing leads for board-level reliability under thermal cycling. Mounting base (drain-connected) provides direct thermal path with 0.77 K/W typical junction-to-mounting-base resistance.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	40 V - Maximum drain-source blocking voltage for 12 V automotive bus protection
R_DS(on)	2.4 mΩ typ @ V_GS = 10 V, I_D = 25 A, T_j = 25 °C - Enables <1 W conduction loss at 70 A
I_D (cont)	120 A @ T_mb = 25 °C - Validated continuous current; limited by PCB thermal design in practice
Q_GD	4.7 nC typ @ V_GS = 4.5 V - Low gate-drain charge supports fast, efficient hard-switching in DC-DC and motor drives
R_th(j-mb)	0.77 K/W typ - Enables high-power dissipation via mounting base; reduces need for large heatsinks
V_GS(th)	1.66 V typ @ I_D = 1 mA - Logic-level turn-on compatible with 3.3 V/5 V microcontrollers
E_AS	50 mJ (unclamped) - Robust single-pulse avalanche capability for inductive load switching

Pinout & Package

Package: LFPAK56 (SOT669), plastic single-ended surface-mounted package with copper clip construction and gull-wing leads. Mounting base (pin mb) is electrically connected to drain and serves as primary thermal and current path.

Pin/Terminal	Circuit Role	Design Meaning
1, 2, 3	Source (S)	Three parallel source terminals reduce package inductance and improve current sharing in high-di/dt applications
4	Gate (G)	Single gate input with 0.8 Ω typical gate resistance - optimized for standard gate drivers without external series resistance
mb	Mounting Base / Drain (D)	Drain-connected copper base; provides low-impedance thermal path and high-current conduction (not a signal pin)

Key Features

Feature	Design Value
Trench 9 Superjunction architecture	Enables 2.4 mΩ R_DS(on) in LFPAK56 footprint - 30% lower than prior-gen TrenchMOS at same die size
AEC-Q101 qualification & 175 °C rating	Validated for automotive under-hood use; supports extended thermal margin in engine bay and transmission modules
LFPAK copper clip + gull-wing leads	Reduces R_DS(on) by 15% and R_th(j-mb) by 25% vs. QFN; eliminates x-ray inspection need via AOI-compatible solder joints
Tight V_GS(th) distribution (1.35–2.05 V)	Enables stable parallel operation of ≥3 devices without current-sharing resistors in high-power solenoid drivers
High avalanche energy (50 mJ)	Withstands unclamped inductive switching events in transmission valve control without derating or snubbers

Applications

Start-Stop Micro-Hybrid Control

Transmission Solenoid Driver

Use Scenario: High-cycle battery disconnect and reconnection during engine stop/start transitions in 12 V mild hybrid vehicles.

IC Role / Device Role / Timing Role: Main power switch controlling starter-generator interface; handles 120 A peak currents with <100 ns switching timing.

Use Value: Low R_DS(on) minimizes voltage drop during cranking; 175 °C rating ensures reliability across ambient temperatures from −40 °C to 125 °C.

Use Scenario: PWM-driven proportional pressure control of hydraulic solenoids in 8-speed automatic transmissions.

IC Role / Device Role / Timing Role: High-side switch operating at 10–20 kHz; requires fast turn-off (13.2 ns fall time) and low Q_GD to limit shoot-through risk.

Use Value: 4.7 nC Q_GD enables clean switching edge; avalanche ruggedness absorbs inductive kickback without clamping diodes.

12 V Motor Load Switch

LED Headlamp Dimming Module

Use Scenario: Bidirectional fan and wiper motor control in body electronics modules with reverse polarity protection.

IC Role / Device Role / Timing Role: Low-side switching element; conducts 80 A continuous with minimal self-heating due to copper clip thermal path.

Use Value: R_th(j-mb) = 0.77 K/W allows direct PCB copper pour cooling - eliminates discrete heatsink in space-constrained modules.

Use Scenario: High-current dimming stage for adaptive LED headlamps requiring precise current regulation up to 10 A per channel.

IC Role / Device Role / Timing Role: Synchronous rectifier in buck converter output stage; leverages low R_DS(on) and fast trr (28.1 ns) for efficiency.

Use Value: 20.4 nC Q_r and softness factor of 0.83 suppress EMI during diode commutation - critical for CISPR 25 Class 5 compliance.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
STL220N4F7AG	40 V, 1.8 mΩ R_DS(on), PowerFLAT 5x6 package, R_th(j-mb) = 1.1 K/W	Higher R_DS(on) but lower gate charge (Q_G(tot) = 18 nC vs. 28 nC); less robust avalanche (35 mJ)	Prefer when gate drive strength is limited and thermal constraints allow higher R_th; avoid in high-avalanche-risk solenoid loads.
ONsemi NTMFS4C09NT1G	40 V, 2.7 mΩ R_DS(on), SO-8FL package, R_th(j-mb) = 0.95 K/W, AEC-Q101 rated	Slightly higher R_DS(on) and thermal resistance; no copper clip - lower current spreading capability	Acceptable for lower-duty-cycle motor control where peak current ≤ 90 A; not recommended for continuous 120 A operation.

Compared with STL220N4F7AG and NTMFS4C09NT1G, BUK9Y2R8-40HX offers superior thermal performance (0.77 K/W), higher avalanche energy (50 mJ), and tighter V_GS(th) - making it optimal for high-reliability, high-current automotive switching where thermal margin and inductive stress are critical.

Availability

BUK9Y2R8-40HX is available at Aetrix Electronics and suitable for automotive start-stop systems, transmission control units, and 12 V motor driver modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for BUK9Y2R8-40HX 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.

BUK9Y2R8-40HX belongs to Nexperia's LFPAK56 automotive MOSFET family, engineered specifically for thermally demanding 12 V power switching in engine control, chassis, and body electronics.

FAQ

Is BUK9Y2R8-40HX pin-compatible with other LFPAK56 MOSFETs?

Yes - BUK9Y2R8-40HX uses the standard SOT669 footprint with identical pin assignment (pins 1–3 = source, pin 4 = gate, mounting base = drain). All LFPAK56 MOSFETs share this mechanical and electrical layout, enabling drop-in replacement within the same voltage/current class.

What is the maximum allowable PCB copper area for thermal relief on the mounting base?

The datasheet recommends ≥200 mm² of 2 oz copper connected directly to the mounting base for optimal thermal performance. Larger areas further reduce R_th(j-amb), but diminishing returns occur beyond 400 mm² unless using internal layers or thermal vias.

Does BUK9Y2R8-40HX require a gate resistor for 5 V MCU drive?

No external gate resistor is required for basic 5 V logic-level drive - its 0.8 Ω typical gate resistance and 28 nC total gate charge allow safe switching with standard microcontroller GPIOs up to ~10 kHz. For >20 kHz PWM, a 2.2–4.7 Ω series resistor improves EMI and dV/dt control.

Can BUK9Y2R8-40HX be used in synchronous rectification applications?

Yes - its low R_DS(on) (2.4 mΩ), fast reverse recovery (t_rr = 28.1 ns), and soft recovery (S = 0.83) make it suitable for high-efficiency synchronous rectification in 12 V buck converters, especially where diode forward voltage drop must be minimized below 0.8 V.

BUK9Y2R8-40HX Specifications

Product attributes: Attribute value

Manufacturer:: Nexperia USA Inc.

Series:: -

Package/Case:: -

Packaging:: Tape & Reel (TR)

Product Status:: Active

FET Type:: -

Technology:: -

Drain to Source Voltage (Vdss):: -

Current - Continuous Drain (Id) @ 25°C:: 120A (Tc)

Drive Voltage (Max Rds On, Min Rds On):: -

Rds On (Max) @ Id, Vgs:: -

Vgs(th) (Max) @ Id:: -

Gate Charge (Qg) (Max) @ Vgs:: -

Vgs (Max):: +16V, -10V

Input Capacitance (Ciss) (Max) @ Vds:: -

FET Feature:: -

Power Dissipation (Max):: 172W (Tc)

Operating Temperature:: -

Grade:: Automotive

Qualification:: AEC-Q101

Mounting Type:: -

Supplier Device Package:: -

BUK9Y2R8-40HX FAQ

1.How can I place an order for BUK9Y2R8-40HX through Aetrix?

Please submit a Request for Quotation (RFQ) for BUK9Y2R8-40HX on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for BUK9Y2R8-40HX reliable?

The price and inventory of BUK9Y2R8-40HX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BUK9Y2R8-40HX is usually 5 days.

3.What payment methods are accepted for BUK9Y2R8-40HX?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BUK9Y2R8-40HX transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BUK9Y2R8-40HX?

BUK9Y2R8-40HX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BUK9Y2R8-40HX order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for BUK9Y2R8-40HX?

For technical support, including BUK9Y2R8-40HX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BUK9Y2R8-40HX requirements.

6.How does Aetrix verify that BUK9Y2R8-40HX is sourced from the original manufacturer or authorized distributors?

All BUK9Y2R8-40HX products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that BUK9Y2R8-40HX meets industry standards.

7.What is the process for return or replacement of BUK9Y2R8-40HX?

All BUK9Y2R8-40HX units undergo pre-shipment inspection (PSI). If there is an issue with BUK9Y2R8-40HX, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The BUK9Y2R8-40HX part is unused and in its original packaging.

Return procedure for BUK9Y2R8-40HX:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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