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

Nexperia USA Inc. BUK9840-55,115

Name: BUK9840-55,115
Brand: Nexperia USA Inc.
SKU: BUK9840-55,115
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BUK9840-55,115

Manufacturer:: Nexperia USA Inc.

Category:: FETs, MOSFETs

Package:: TO-261-4, TO-261AA

Datasheet:: BUK9840-55,115.pdf

Description:: MOSFET N-CH 55V 5A SOT223

Quantity:: RFQ Add To RFQ list

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Product details

Overview

BUK9840-55 from NXP Semiconductors is an AEC-Q101-qualified N-channel TrenchMOS logic-level power MOSFET in SOT223 (SC-73) package, designed for automotive power switching with 55 V V_DS, 10.7 A continuous drain current at T_sp = 25 °C, 30–40 mΩ R_DS(on) at V_GS = 5 V and T_j = 25 °C, and integrated ESD protection (2 kV HBM). It serves as a robust high-side or low-side switch in engine control modules and body electronics.

For engineers reviewing the BUK9840-55 datasheet, BUK9840-55 pinout, BUK9840-55 application, or BUK9840-55 equivalent, key selection criteria include logic-level gate drive compatibility (V_GS(th) = 1–2 V), avalanche ruggedness (60 mJ unclamped), thermal resistance (R_th(j-sp) = 12–15 K/W), and automotive qualification status.

Technical Context

This device implements TrenchMOS technology to achieve low on-resistance and fast switching (t_d(on) = 17–25 ns, t_f = 70–105 ns) under 5 V logic-level gate drive. Its dual-drain pin configuration (Pins 1 & 4) supports enhanced thermal dissipation via the exposed heatsink pad in the SOT223 package.

The integrated source-drain diode (V_SD = 0.85–1.1 V at I_S = 5 A) enables freewheeling in inductive loads, while its non-repetitive avalanche rating (E_DS(AL)S = 60 mJ) provides transient overvoltage tolerance in automotive 12 V systems.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	55 V - Maximum drain-source blocking voltage compatible with 12 V automotive battery systems with load-dump margin.
I_D (continuous)	10.7 A at T_sp = 25 °C - Supports medium-power loads such as fuel pumps, radiator fans, and solenoid drivers.
R_DS(on)	30–40 mΩ at V_GS = 5 V, T_j = 25 °C - Enables <1 W conduction loss at 5 A, reducing thermal stress in compact PCB layouts.
E_DS(AL)S	60 mJ unclamped - Withstands inductive kickback from relays and motors without external snubbers in many automotive designs.
V_GS(th)	1–2 V - Fully enhances with standard 3.3 V or 5 V microcontroller GPIO, eliminating need for gate driver ICs.
R_th(j-sp)	12–15 K/W - Enables direct thermal coupling to copper pour or heatsink pad, critical for sustained operation in engine bay environments.
C_iss	1050–1400 pF - Low input capacitance reduces gate drive power and improves switching efficiency at 10–100 kHz PWM frequencies.

Pinout & Package

SOT223 (SC-73) plastic surface-mounted package with increased heatsink area; 4 leads, Pin 3 is source, Pins 1 & 4 are internally connected drains, Pin 2 is gate.

Pin/Terminal	Circuit Role	Design Meaning
1	Drain	Primary high-current output terminal; electrically tied to Pin 4 for parallel current handling and improved thermal path.
2	Gate	Logic-level control input; requires no level-shifting for 3.3 V/5 V MCU outputs due to low V_GS(th).
3	Source	Reference node for gate drive and current return; connects directly to ground plane or low-side switch common point.
4	Drain	Secondary drain terminal; bonded to Pin 1 to reduce package inductance and enhance thermal spreading to PCB copper.

Key Features

Feature	Design Value
AEC-Q101 qualified	Validated for automotive mission-critical applications including engine management and chassis control per JESD22-A108.
Integrated ESD protection	2 kV HBM rating eliminates need for external TVS diodes in typical board-level ESD environments.
Low R_DS(on) at 5 V	30 mΩ typical ensures minimal I²R heating during continuous operation in space-constrained modules.
Dual-drain configuration	Pins 1 & 4 provide redundant current paths and lower thermal resistance to solder point (R_th(j-sp) ≤ 15 K/W).
Avalanche-rated	60 mJ unclamped energy rating allows safe operation under inductive switching without external clamping circuits.

Applications

Engine Control Unit (ECU) Fuel Pump Driver

Body Control Module (BCM) Headlight Switch

Use Scenario: Driving 12 V DC brushed fuel pump motor with peak currents up to 9 A and inductive flyback transients.

IC Role / Device Role / Timing Role: Low-side power switch controlled by ECU microcontroller PWM signal; handles repetitive turn-on/off cycling during engine start and idle.

Use Value: 5 V logic compatibility eliminates gate driver, while 60 mJ avalanche rating absorbs pump coil energy without snubber components.

Use Scenario: Switching halogen headlight loads (55 W, ~4.6 A) in response to vehicle lighting control signals.

IC Role / Device Role / Timing Role: High-side or low-side load switch enabling precise on/off control and diagnostics via current sensing at source.

Use Value: 10.7 A continuous rating accommodates cold filament inrush; AEC-Q101 qualification ensures reliability across -40 °C to +125 °C ambient.

Transmission Control Solenoid Driver

Electric Power Steering (EPS) Motor Phase Switch

Use Scenario: Controlling hydraulic pressure solenoids (12 V, 1–2 A steady-state, 3–4 A inrush) in automatic transmission valve bodies.

IC Role / Device Role / Timing Role: Precision current-regulated switch using PWM feedback; operates in high-vibration, high-temperature under-hood environment.

Use Value: Low R_DS(on) minimizes self-heating during duty-cycle modulation; TrenchMOS structure ensures stable threshold across temperature.

Use Scenario: Half-bridge phase leg in 12 V EPS motor driver, switching at 10–20 kHz with bidirectional current flow.

IC Role / Device Role / Timing Role: Low-side switch in H-bridge topology; conducts reverse current through internal body diode during freewheeling.

Use Value: Fast switching (t_f ≤ 105 ns) and low C_iss reduce switching losses; source-drain diode V_SD ≤ 1.1 V limits freewheeling conduction loss.

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
STL130N5LF5	55 V, 130 A rated but in DPAK; R_DS(on) = 3.5 mΩ at 10 V; requires 10 V gate drive for full enhancement.	Higher current capacity but not logic-level; unsuitable for direct 3.3 V MCU drive without level shift.	Select only if higher current and thermal mass justify larger footprint and added gate drive complexity.
ON Semiconductor NTMFS4C09NT1G	40 V, 120 A, SO-8FL; R_DS(on) = 3.2 mΩ at 10 V; logic-level version (NTMFS4C09NLT1G) has 4.2 mΩ at 4.5 V.	Lower V_DS rating; not suitable for 55 V load-dump conditions in 12 V automotive systems.	Use only in 5 V or low-voltage auxiliary subsystems where 40 V rating is sufficient and space is constrained.

Compared with STL130N5LF5 and NTMFS4C09NT1G, BUK9840-55 uniquely balances 55 V rating, true logic-level operation (1–2 V V_GS(th)), SOT223 thermal performance, and AEC-Q101 compliance-making it optimal for cost-sensitive, space-limited automotive power switches requiring no gate driver.

Availability

BUK9840-55 is available at Aetrix Electronics and suitable for automotive engine control units, body electronics modules, and industrial power supplies requiring stable component supply and long-term lifecycle support.

Supply support for BUK9840-55 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

NXP Semiconductors is a Dutch semiconductor company specializing in secure connectivity solutions for automotive, industrial, and IoT applications, with core expertise in RF, analog, and power management technologies.

The BUK9840-55 belongs to NXP's TrenchMOS logic-level power MOSFET product line, engineered specifically for AEC-Q101-compliant automotive power switching where space, thermal efficiency, and direct microcontroller interfacing are critical.

FAQ

Is BUK9840-55 suitable for high-side switching configurations?

Yes, BUK9840-55 supports high-side switching when used with appropriate gate drive circuitry that can pull the gate above the source potential. Its 10 V maximum V_GS rating and 55 V V_DS allow operation in 12 V systems with margin, though external level-shifting may be needed for full enhancement in floating-source topologies.

What is the maximum junction temperature and how does R_DS(on) vary with temperature?

The absolute maximum junction temperature is 150 °C. R_DS(on) increases with temperature: at T_j = 150 °C and V_GS = 5 V, R_DS(on) rises to 74 mΩ (typical), approximately 2.5× its 25 °C value-designers must derate current accordingly using Fig. 10's normalized R_DS(on) curve.

Does BUK9840-55 have a built-in body diode, and what are its characteristics?

Yes, it features an integrated source-drain body diode with forward voltage V_SD = 0.85–1.1 V at I_S = 5 A and T_j = 25 °C. Reverse recovery time t_rr is 45 ns (typical), and recovered charge Q_r is 0.3 µC, enabling efficient freewheeling in inductive switching applications without external diodes.

Can BUK9840-55 be paralleled with identical devices for higher current handling?

Yes, its positive temperature coefficient of R_DS(on) (see Fig. 10) promotes inherent current sharing. For reliable paralleling, ensure matched PCB layout (symmetrical trace lengths, shared thermal pad), identical gate drive impedance, and individual gate resistors to suppress oscillation-verified in NXP AN10872 application note.

BUK9840-55,115 Specifications

Product attributes: Attribute value

Manufacturer:: Nexperia USA Inc.

Series:: TrenchMOS™

Package/Case:: TO-261-4, TO-261AA

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 55 V

Current - Continuous Drain (Id) @ 25°C:: 5A (Ta)

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

Rds On (Max) @ Id, Vgs:: 40mOhm @ 5A, 5V

Vgs(th) (Max) @ Id:: 2V @ 1mA

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

Vgs (Max):: ±10V

Input Capacitance (Ciss) (Max) @ Vds:: 1400 pF @ 25 V

FET Feature:: -

Power Dissipation (Max):: 1.8W (Ta)

Operating Temperature:: -55°C ~ 150°C (TJ)

Grade:: Automotive

Qualification:: AEC-Q101

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-223

BUK9840-55,115 FAQ

1.How can I place an order for BUK9840-55,115 through Aetrix?

Please submit a Request for Quotation (RFQ) for BUK9840-55,115 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 BUK9840-55,115 reliable?

The price and inventory of BUK9840-55,115 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BUK9840-55,115 is usually 5 days.

3.What payment methods are accepted for BUK9840-55,115?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BUK9840-55,115 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BUK9840-55,115?

BUK9840-55,115 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BUK9840-55,115 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 BUK9840-55,115?

For technical support, including BUK9840-55,115 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BUK9840-55,115 requirements.

6.How does Aetrix verify that BUK9840-55,115 is sourced from the original manufacturer or authorized distributors?

All BUK9840-55,115 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 BUK9840-55,115 meets industry standards.

7.What is the process for return or replacement of BUK9840-55,115?

All BUK9840-55,115 units undergo pre-shipment inspection (PSI). If there is an issue with BUK9840-55,115, 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 BUK9840-55,115 part is unused and in its original packaging.

Return procedure for BUK9840-55,115:

1.Submit a request within 90 days.

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

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