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

NXP Semiconductors BUK9E2R3-40E,127

Name: BUK9E2R3-40E,127
Brand: NXP Semiconductors
SKU: BUK9E2R3-40E,127
Price: 2.40 USD
Availability: InStock
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Part No.:: BUK9E2R3-40E,127

Manufacturer:: NXP Semiconductors

Category:: FETs, MOSFETs

Package:: TO-262-3 Long Leads, I2PAK, TO-262AA

Datasheet:: BUK9E2R3-40E,127.pdf

Description:: MOSFET N-CH 40V 120A I2PAK

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Product details

Overview

BUK9E2R3-40E from Nexperia is an AEC-Q101-qualified N-channel TrenchMOS logic-level power MOSFET in I2PAK (SOT226) package, rated for 40 V V_DS, 120 A continuous drain current at T_mb = 25 °C, and 2.1 mΩ typical R_DS(on) at V_GS = 5 V and T_j = 25 °C. It serves as a high-current, thermally robust switching element in automotive 12 V systems including start-stop micro-hybrid control and transmission actuation.

For engineers reviewing the BUK9E2R3-40E datasheet, BUK9E2R3-40E pinout, BUK9E2R3-40E application, or BUK9E2R3-40E equivalent, key selection criteria include its true logic-level gate drive (V_GS(th) ≥ 0.5 V at 175 °C), 175 °C junction rating, repetitive avalanche capability, and mounting-base thermal resistance of 0.51 K/W - critical for high-reliability under-hood power switching.

Technical Context

This device employs TrenchMOS technology to achieve low on-resistance with logic-level gate compatibility, enabling direct drive from 3.3 V or 5 V microcontrollers without gate drivers. Its internal structure integrates a robust source-drain diode with 45 ns reverse recovery time and 62 nC recovered charge, supporting synchronous rectification and inductive load commutation.

The MOSFET features fully specified dynamic parameters including 87.8 nC total gate charge, 29.6 nC gate-drain charge, and tightly controlled parasitic inductances (L_D = 2.5 nH, L_S = 7.5 nH), ensuring predictable switching behavior in high-frequency PWM applications up to several hundred kHz.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	40 V - Maximum drain-source blocking voltage; defines use in 12 V automotive systems with transient overvoltage margin.
R_DS(on) @ V_GS=5 V, T_j=25 °C	2.1 mΩ typ - Enables <1 W conduction loss at 25 A, reducing heatsink requirements in space-constrained modules.
I_D continuous @ T_mb=25 °C	120 A - Package-limited current; supports high-power solenoid, motor, and lamp loads without external current sharing.
T_j max	175 °C - Qualified for under-hood operation; enables stable performance in engine bay environments without derating penalties.
R_th(j-mb)	0.51 K/W - Low thermal resistance to mounting base allows efficient heat transfer to PCB copper or heatsink, critical for sustained high-current duty cycles.
Q_G(tot)	87.8 nC - Gate charge value determines required driver peak current and switching energy; compatible with standard logic-level gate drivers.
E_AS	622 mJ - Non-repetitive avalanche energy rating supports robustness against inductive kickback in transmission and starter circuits.

Pinout & Package

I2PAK (SOT226) package with isolated mounting base electrically connected to the drain terminal; designed for surface-mount assembly with through-hole thermal anchoring via the metal base. Package dimensions: 15.0 × 10.3 × 4.5 mm (L × W × H), with 2.54 mm lead pitch.

Pin/Terminal	Circuit Role	Design Meaning
1 (G)	Gate	Logic-level input controlling channel conduction; threshold voltage ≥0.5 V at 175 °C ensures reliable turn-on across full temperature range.
2 (D)	Drain	Main high-side power path; internally bonded to mounting base for low-inductance, high-current return path and thermal conduction.
3 (S)	Source	Power return node and reference for gate drive; internal source inductance of 7.5 nH impacts switching speed and ringing in high-dI/dt applications.
Mounting base (mb)	Drain connection	Electrically tied to drain; provides primary thermal interface and mechanical anchoring; must be soldered to large copper pour or heatsink.

Key Features

Feature	Design Value
AEC-Q101 qualified	Validated for automotive-grade reliability including temperature cycling, humidity testing, and mechanical shock per automotive stress standards.
Repetitive avalanche rated	Withstands repeated inductive energy spikes without degradation - essential for transmission solenoid and fuel injector drivers.
True logic-level gate	V_GS(th) ≥ 0.5 V at 175 °C ensures guaranteed turn-on from standard 3.3 V/5 V MCU GPIOs even at maximum operating temperature.
175 °C junction rating	Enables operation in high-ambient under-hood locations without thermal shutdown or parameter drift beyond specification limits.
Low R_DS(on) × Q_G figure-of-merit	2.1 mΩ × 87.8 nC = 184 mΩ·nC - balances conduction and switching losses for high-efficiency 10–200 kHz PWM in motor control.

Applications

Start-Stop Micro-Hybrid Control	Transmission Solenoid Driver
Use Scenario: Controlling high-current battery disconnect and starter motor engagement during engine auto-stop and restart cycles in 12 V micro-hybrid vehicles. IC Role / Device Role / Timing Role: High-side power switch managing bidirectional 12 V bus isolation and cranking current delivery with sub-100 µs response. Use Value: 120 A continuous rating and 988 A pulsed current support enable single-device implementation without paralleling; 175 °C rating prevents thermal shutdown during repeated cranking events.	Use Scenario: Driving electro-hydraulic transmission solenoids requiring precise 12 V PWM current regulation for gear shift timing and pressure control. IC Role / Device Role / Timing Role: Low-loss, fast-switching power stage delivering up to 25 A average current with 45 ns diode reverse recovery for clean turn-off. Use Value: 2.1 mΩ R_DS(on) minimizes self-heating during 50% duty cycle operation; integrated source-drain diode eliminates need for external flyback component.
Automotive Lamp Load Switching	Engine Cooling Fan Controller
Use Scenario: Replacing electromechanical relays for headlamp, foglamp, and daytime running light (DRL) control in modern lighting modules. IC Role / Device Role / Timing Role: Robust load switch handling inrush currents up to 988 A peak while providing short-circuit and overtemperature protection. Use Value: Repetitive avalanche rating absorbs lamp filament cold-resistance surges; AEC-Q101 qualification ensures >15-year field life in vibration-prone lighting housings.	Use Scenario: Regulating 12 V brushless DC cooling fan motors in engine compartments where ambient temperatures exceed 105 °C. IC Role / Device Role / Timing Role: Thermally resilient PWM switch operating continuously at T_j up to 175 °C with minimal derating. Use Value: 0.51 K/W R_th(j-mb) enables direct thermal coupling to aluminum heatsink, maintaining safe junction temperature even at full 120 A conduction.

Start-Stop Micro-Hybrid Control

Transmission Solenoid Driver

Use Scenario: Controlling high-current battery disconnect and starter motor engagement during engine auto-stop and restart cycles in 12 V micro-hybrid vehicles.

IC Role / Device Role / Timing Role: High-side power switch managing bidirectional 12 V bus isolation and cranking current delivery with sub-100 µs response.

Use Value: 120 A continuous rating and 988 A pulsed current support enable single-device implementation without paralleling; 175 °C rating prevents thermal shutdown during repeated cranking events.

Use Scenario: Driving electro-hydraulic transmission solenoids requiring precise 12 V PWM current regulation for gear shift timing and pressure control.

IC Role / Device Role / Timing Role: Low-loss, fast-switching power stage delivering up to 25 A average current with 45 ns diode reverse recovery for clean turn-off.

Use Value: 2.1 mΩ R_DS(on) minimizes self-heating during 50% duty cycle operation; integrated source-drain diode eliminates need for external flyback component.

Automotive Lamp Load Switching

Engine Cooling Fan Controller

Use Scenario: Replacing electromechanical relays for headlamp, foglamp, and daytime running light (DRL) control in modern lighting modules.

IC Role / Device Role / Timing Role: Robust load switch handling inrush currents up to 988 A peak while providing short-circuit and overtemperature protection.

Use Value: Repetitive avalanche rating absorbs lamp filament cold-resistance surges; AEC-Q101 qualification ensures >15-year field life in vibration-prone lighting housings.

Use Scenario: Regulating 12 V brushless DC cooling fan motors in engine compartments where ambient temperatures exceed 105 °C.

IC Role / Device Role / Timing Role: Thermally resilient PWM switch operating continuously at T_j up to 175 °C with minimal derating.

Use Value: 0.51 K/W R_th(j-mb) enables direct thermal coupling to aluminum heatsink, maintaining safe junction temperature even at full 120 A conduction.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
STL220N4F7AG	40 V, 220 A, R_DS(on) = 1.7 mΩ @ 10 V; requires 10 V gate drive for optimal R_DS(on); not AEC-Q101 qualified.	Higher current capacity but lacks automotive qualification and true logic-level gate; suitable for industrial motor drives only.	Select STL220N4F7AG only if gate drive voltage ≥8 V is available and AEC-Q101 compliance is not required.
IRF1404ZLPBF	40 V, 180 A, R_DS(on) = 3.8 mΩ @ 10 V; non-logic-level (V_GS(th) = 2–4 V); TO-220AB package; no AEC-Q101 rating.	Larger footprint, higher R_DS(on), and no high-temperature gate assurance; limited to non-automotive 12 V switching.	IRF1404ZLPBF may serve as cost-sensitive alternative in non-automotive designs where gate drive ≥8 V is assured and thermal performance is less critical.

Compared with STL220N4F7AG and IRF1404ZLPBF, the BUK9E2R3-40E uniquely combines AEC-Q101 qualification, true logic-level gate operation down to 0.5 V at 175 °C, and industry-leading 2.1 mΩ R_DS(on) in a thermally optimized SOT226 package - making it the only drop-in solution for safety-critical automotive power switching where reliability, temperature margin, and MCU-compatible drive are mandatory.

Availability

BUK9E2R3-40E is available at Aetrix Electronics and suitable for automotive start-stop systems, transmission control units, and 12 V high-current lamp switching requiring stable component supply across extended production lifecycles.

Supply support for BUK9E2R3-40E 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 leader in discrete, logic, and PowerMOS semiconductors, formed in 2017 from the former NXP Standard Products business. It focuses on high-volume, high-reliability components for automotive, industrial, computing, and consumer markets.

The BUK9E2R3-40E belongs to Nexperia's TrenchMOS automotive logic-level power MOSFET product line, engineered specifically for thermally demanding, safety-critical 12 V automotive power switching applications requiring AEC-Q101 compliance and long-term supply stability.

FAQ

What is the maximum continuous drain current rating for BUK9E2R3-40E?

The BUK9E2R3-40E has a maximum continuous drain current of 120 A at mounting base temperature (T_mb) = 25 °C, as limited by package thermal capability. At T_mb = 100 °C, the rating remains 120 A due to thermal design margin, but actual usable current depends on heatsinking and ambient conditions. The BUK9E2R3-40E datasheet specifies this value in Figure 1 and Table 5.

Is BUK9E2R3-40E suitable for driving inductive loads like solenoids and motors?

Yes, the BUK9E2R3-40E is explicitly designed for inductive load switching, featuring repetitive avalanche rating (622 mJ), fast source-drain diode (t_rr = 45 ns, Q_r = 62 nC), and robust gate drive characteristics. Its 175 °C junction rating and AEC-Q101 qualification make it ideal for automotive solenoid and BLDC motor control in transmission and cooling systems.

Does BUK9E2R3-40E require a gate driver IC when used with a 3.3 V microcontroller?

No, the BUK9E2R3-40E does not require an external gate driver when driven by a 3.3 V or 5 V microcontroller. Its true logic-level gate ensures V_GS(th) ≥ 0.5 V even at 175 °C, and R_DS(on) remains low (≤4.8 mΩ) at V_GS = 5 V, enabling full enhancement directly from standard MCU GPIOs.

What is the thermal resistance from junction to mounting base for BUK9E2R3-40E?

The BUK9E2R3-40E has a maximum thermal resistance R_th(j-mb) of 0.51 K/W, measured from silicon junction to the metal mounting base. This low value enables efficient heat transfer to PCB copper or external heatsinks, supporting high-power operation without excessive temperature rise - a key advantage over TO-220 or DPAK alternatives.

Can BUK9E2R3-40E replace older NXP BUK9Y series MOSFETs in existing designs?

The BUK9E2R3-40E is a direct functional and pin-compatible upgrade to earlier BUK9Y-series devices (e.g., BUK9Y2R3-40E), offering identical I2PAK (SOT226) footprint, same pinout, and improved R_DS(on) and thermal performance. It maintains full backward compatibility while adding enhanced avalanche ruggedness and tighter parametric control.

BUK9E2R3-40E,127 Specifications

Product attributes: Attribute value

Manufacturer:: NXP Semiconductors

Series:: TrenchMOS™

Package/Case:: TO-262-3 Long Leads, I2PAK, TO-262AA

Packaging:: Tube

Product Status:: Obsolete

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 40 V

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

Drive Voltage (Max Rds On, Min Rds On):: 5V, 10V

Rds On (Max) @ Id, Vgs:: 2.2mOhm @ 25A, 10V

Vgs(th) (Max) @ Id:: 2.1V @ 1mA

Gate Charge (Qg) (Max) @ Vgs:: 87.8 nC @ 5 V

Vgs (Max):: ±10V

Input Capacitance (Ciss) (Max) @ Vds:: 13160 pF @ 25 V

FET Feature:: -

Power Dissipation (Max):: 293W (Tc)

Operating Temperature:: -55°C ~ 175°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: I2PAK

BUK9E2R3-40E,127 FAQ

1.How can I place an order for BUK9E2R3-40E,127 through Aetrix?

Please submit a Request for Quotation (RFQ) for BUK9E2R3-40E,127 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 BUK9E2R3-40E,127 reliable?

The price and inventory of BUK9E2R3-40E,127 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BUK9E2R3-40E,127 is usually 5 days.

3.What payment methods are accepted for BUK9E2R3-40E,127?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BUK9E2R3-40E,127 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BUK9E2R3-40E,127?

BUK9E2R3-40E,127 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BUK9E2R3-40E,127 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 BUK9E2R3-40E,127?

For technical support, including BUK9E2R3-40E,127 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BUK9E2R3-40E,127 requirements.

6.How does Aetrix verify that BUK9E2R3-40E,127 is sourced from the original manufacturer or authorized distributors?

All BUK9E2R3-40E,127 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 BUK9E2R3-40E,127 meets industry standards.

7.What is the process for return or replacement of BUK9E2R3-40E,127?

All BUK9E2R3-40E,127 units undergo pre-shipment inspection (PSI). If there is an issue with BUK9E2R3-40E,127, 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 BUK9E2R3-40E,127 part is unused and in its original packaging.

Return procedure for BUK9E2R3-40E,127:

1.Submit a request within 90 days.

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

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