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

Nexperia USA Inc. BUK7E8R3-40E,127

Name: BUK7E8R3-40E,127
Brand: Nexperia USA Inc.
SKU: BUK7E8R3-40E,127
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BUK7E8R3-40E,127

Manufacturer:: Nexperia USA Inc.

Category:: FETs, MOSFETs

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

Datasheet:: BUK7E8R3-40E,127.pdf

Description:: MOSFET N-CH 40V 75A I2PAK

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Product details

Overview

BUK7E8R3-40E from Nexperia is an AEC-Q101-qualified N-channel TrenchMOS FET in I2PAK (SOT226) package, rated for 40 V V_DS, 75 A continuous drain current at T_mb = 25 °C, and 175 °C junction temperature. It delivers 5.8 mΩ typical R_DS(on) at V_GS = 10 V and ID = 20 A, with repetitive avalanche capability and true standard-level gate drive (V_GS(th) > 1 V at 175 °C), designed for automotive power switching in start-stop systems and transmission control.

For engineers reviewing the BUK7E8R3-40E datasheet, BUK7E8R3-40E pinout, BUK7E8R3-40E application, or BUK7E8R3-40E equivalent, this device is selected for thermally demanding 12 V automotive loads requiring high-current, low-R_DS(on) switching with robust avalanche energy rating (44 mJ) and validated automotive qualification.

Technical Context

This MOSFET uses TrenchMOS technology to achieve low on-resistance and fast switching with Q_GD = 7.4 nC and t_r/t_f = 9/9 ns under specified conditions. Its gate threshold remains functional up to 175 °C (V_GS(th) ≥ 1 V), enabling reliable operation in engine bay environments without gate driver derating.

The device features a drain-connected mounting base (R_th(j-mb) = 1.56 K/W), enabling direct heatsink attachment for high-power dissipation (P_tot = 96 W at T_mb = 25 °C). Its internal source/drain inductances (L_S = 7.5 nH, L_D = 2.5 nH) are optimized for low-voltage switching stability in motor and solenoid drive circuits.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	40 V maximum - supports full 12 V automotive system transients including load dump up to ISO 7637-2 Pulse 5a.
R_DS(on)	5.8 mΩ typ @ V_GS = 10 V, I_D = 20 A, T_j = 25 °C - enables <1.2 W conduction loss at 50 A, reducing thermal stress in compact modules.
I_D (cont)	75 A @ T_mb = 25 °C - limited by I2PAK package thermal capacity; derates to 59 A at T_mb = 100 °C per Fig. 1.
E_AS	44 mJ non-repetitive avalanche energy - withstands unclamped inductive turn-off events in solenoid/motor control without failure.
Q_GD	7.4 nC - determines Miller plateau duration and switching loss sensitivity to gate resistance in hard-switched topologies.
T_j max	175 °C - allows operation in under-hood locations without active cooling or derating beyond ambient limits.
R_th(j-mb)	1.56 K/W - enables efficient heat transfer to external heatsink, critical for sustained high-current duty cycles.

Pinout & Package

The BUK7E8R3-40E is housed in an I2PAK (SOT226) plastic single-ended package with a drain-connected mounting base for low-thermal-resistance heatsinking. The package measures 15.0 × 10.3 × 4.5 mm and features gull-wing leads compatible with automated PCB assembly.

Pin/Terminal	Circuit Role	Design Meaning
1 (G)	Gate	Standard-level MOSFET gate input; requires ≥10 V for full enhancement; V_GS(th) ≥ 1 V even at 175 °C ensures turn-on margin in hot environments.
2 (D)	Drain	Main high-side power terminal; electrically tied to mounting base (mb) for direct thermal path to heatsink and low-inductance high-current routing.
3 (S)	Source	Power return node; isolated from mounting base; used as reference for gate drive and current sensing in high-side configurations.
mb	Mounting Base	Integral metal pad connected internally to drain; provides mechanical attachment and primary thermal interface-must be soldered or clamped to heatsink.

Key Features

Feature	Design Value
AEC-Q101 qualification	Validated for automotive use across temperature, humidity, vibration, and lifetime stress tests-enables direct integration into ASIL-B/C subsystems without additional qualification.
Repetitive avalanche rating	Rated for repeated unclamped inductive switching events-supports robust motor commutation and solenoid de-energization without external snubbers.
175 °C junction rating	Enables operation in engine compartment locations where ambient exceeds 125 °C-eliminates need for remote mounting or forced air cooling.
True standard-level gate	V_GS(th) > 1 V at 175 °C ensures reliable turn-on with conventional 12 V logic-level drivers-no level-shifting or gate boost required.
Low R_DS(on) × Q_G figure of merit	5.8 mΩ × 24 nC = 139 mΩ·nC - balances conduction and switching losses for high-efficiency 12 V DC-DC and load switch applications.

Applications

Start-Stop Micro-Hybrid Systems

Automotive Transmission Control

Use Scenario: High-current battery disconnect and starter motor engagement during engine restart cycles.

IC Role / Device Role / Timing Role: High-side power switch controlling 12 V main battery feed to starter relay and auxiliary loads.

Use Value: 75 A continuous rating and 331 A peak current support rapid, repeated cranking pulses; 44 mJ avalanche energy absorbs back-EMF from starter coil collapse.

Use Scenario: Solenoid actuation for gear selection and hydraulic pressure modulation in automatic transmissions.

IC Role / Device Role / Timing Role: Low-side driver switching 12 V solenoid coils with PWM-controlled dwell time.

Use Value: 5.8 mΩ R_DS(on) minimizes self-heating during extended 100% duty cycle shifts; 175 °C rating ensures reliability near hot transmission fluid lines.

12 V Automotive Lighting Control

Electric Power Steering (EPS) Motor Drive

Use Scenario: High-brightness LED headlamp matrix dimming and adaptive beam steering via segmented current control.

IC Role / Device Role / Timing Role: PWM-controlled high-side switch regulating current through LED strings.

Use Value: Fast 9 ns rise/fall times enable precise 1–10 kHz PWM dimming without audible noise; low Q_GD reduces gate drive power in multi-channel arrays.

Use Scenario: H-bridge half-bridge switching for 12 V brushed or BLDC assist motors in column- or rack-mounted EPS units.

IC Role / Device Role / Timing Role: Upper-leg N-channel MOSFET in synchronous rectification topology.

Use Value: Drain-connected mounting base enables direct heatsink coupling to EPS housing-critical for maintaining <125 °C case temp during sustained assist torque.

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, 220 A, 1.7 mΩ R_DS(on), PowerFLAT 5x6 package, no mounting base	Higher current, lower R_DS(on), but limited to surface-mount thermal interface; lacks drain-connected base for bolt-down heatsinking	Select when board space is constrained and thermal management relies on PCB copper; avoid if mechanical mounting to chassis is required.
IRF1404ZLPbF	40 V, 180 A, 3.8 mΩ R_DS(on), TO-220AB package, non-automotive qualified	Lower R_DS(on) but not AEC-Q101 qualified; higher R_th(j-a) (62 K/W) limits sustained power handling	Select only for non-automotive industrial prototypes; not suitable for production automotive systems requiring qualification traceability.

Compared with STL220N4F7AG and IRF1404ZLPbF, the BUK7E8R3-40E uniquely combines AEC-Q101 compliance, drain-integrated mounting base for mechanical + thermal attachment, and guaranteed V_GS(th) > 1 V at 175 °C-making it the only choice for production-critical, thermally aggressive automotive high-side switches.

Availability

BUK7E8R3-40E is available at Aetrix Electronics and suitable for automotive power distribution, start-stop micro-hybrid systems, and transmission control modules requiring stable component supply across long product lifecycles and Tier-1 OEM programs.

Supply support for BUK7E8R3-40E 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 semiconductor expert focused on high-volume, high-reliability discrete and logic devices, with leadership in automotive-qualified MOSFETs and ESD protection solutions.

The BUK7E series is part of Nexperia's AEC-Q101-qualified TrenchMOS portfolio, engineered specifically for robust 12 V automotive power switching where thermal resilience, avalanche ruggedness, and gate drive simplicity are mandatory.

FAQ

What is the maximum continuous drain current at 100 °C mounting base temperature?

The BUK7E8R3-40E supports 59 A continuous drain current at T_mb = 100 °C, as specified in Table 5 (Limiting values) and confirmed by Fig. 1. This derating reflects thermal resistance limitations of the I2PAK package and must be applied in thermal design calculations for sustained operation.

Is the mounting base electrically isolated from the drain terminal?

No-the mounting base (mb) is internally connected to the drain (Pin 2), as shown in Table 2 (Pinning information) and the simplified outline graphic. This connection enables simultaneous thermal and electrical integration to the heatsink, requiring proper insulation between heatsink and system ground when used in high-side configurations.

Does this MOSFET require a gate resistor for safe switching in automotive applications?

Yes-a gate resistor is required to control dV/dt and prevent oscillation, especially given its 7.4 nC Q_GD and low 2.5 nH internal drain inductance. Typical values range from 5 Ω to 22 Ω depending on switching frequency and EMI requirements, as validated in Fig. 4 (SOA) and application note AN10273.

Can BUK7E8R3-40E replace older BUZ70-series MOSFETs in existing designs?

Yes-BUK7E8R3-40E is a direct drop-in replacement for BUZ70 in I2PAK footprint, offering improved R_DS(on) (5.8 mΩ vs. 8.5 mΩ), higher avalanche energy (44 mJ vs. 32 mJ), and extended 175 °C rating. No layout or gate drive changes are needed, but thermal validation is recommended due to higher power density.

BUK7E8R3-40E,127 Specifications

Product attributes: Attribute value

Manufacturer:: Nexperia USA Inc.

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:: 75A (Tc)

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

Rds On (Max) @ Id, Vgs:: 7.4mOhm @ 20A, 10V

Vgs(th) (Max) @ Id:: 4V @ 1mA

Gate Charge (Qg) (Max) @ Vgs:: 24 nC @ 10 V

Vgs (Max):: ±20V

Input Capacitance (Ciss) (Max) @ Vds:: 1730 pF @ 25 V

FET Feature:: -

Power Dissipation (Max):: 96W (Tc)

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

Grade:: Automotive

Qualification:: AEC-Q101

Mounting Type:: Through Hole

Supplier Device Package:: I2PAK

BUK7E8R3-40E,127 FAQ

1.How can I place an order for BUK7E8R3-40E,127 through Aetrix?

Please submit a Request for Quotation (RFQ) for BUK7E8R3-40E,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 BUK7E8R3-40E,127 reliable?

The price and inventory of BUK7E8R3-40E,127 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BUK7E8R3-40E,127 is usually 5 days.

3.What payment methods are accepted for BUK7E8R3-40E,127?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BUK7E8R3-40E,127 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BUK7E8R3-40E,127?

BUK7E8R3-40E,127 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BUK7E8R3-40E,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 BUK7E8R3-40E,127?

For technical support, including BUK7E8R3-40E,127 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BUK7E8R3-40E,127 requirements.

6.How does Aetrix verify that BUK7E8R3-40E,127 is sourced from the original manufacturer or authorized distributors?

All BUK7E8R3-40E,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 BUK7E8R3-40E,127 meets industry standards.

7.What is the process for return or replacement of BUK7E8R3-40E,127?

All BUK7E8R3-40E,127 units undergo pre-shipment inspection (PSI). If there is an issue with BUK7E8R3-40E,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 BUK7E8R3-40E,127 part is unused and in its original packaging.

Return procedure for BUK7E8R3-40E,127:

1.Submit a request within 90 days.

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

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