Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

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

Nexperia USA Inc. BUK9508-55B,127

Name: BUK9508-55B,127
Brand: Nexperia USA Inc.
SKU: BUK9508-55B,127
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: BUK9508-55B,127

Manufacturer:: Nexperia USA Inc.

Category:: FETs, MOSFETs

Package:: TO-220-3

Datasheet:: BUK9508-55B,127.pdf

Description:: MOSFET N-CH 55V 75A TO220AB

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:7,697

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

BUK9508-55B from NXP Semiconductors is a logic-level N-channel TrenchMOS FET in TO-220AB (SOT78) package, rated for 55 V V_DS, 75 A continuous drain current at T_mb = 25 °C, and 175 °C junction temperature. It delivers 6.2 mΩ R_DS(on) at V_GS = 10 V and ID = 25 A, and is AEC-Q101 qualified for automotive power switching in 12 V/24 V systems.

For engineers reviewing the BUK9508-55B datasheet, BUK9508-55B pinout, BUK9508-55B application, or BUK9508-55B equivalent, this page provides verified technical context, thermal design values, gate-drive compatibility with 5 V logic sources, and validated alternatives for automotive load control.

Technical Context

This device uses TrenchMOS technology to achieve low on-resistance and high avalanche ruggedness (352 mJ unclamped), enabling robust operation under inductive load switching. Its gate threshold voltage (1.1–2.0 V at T_j = 25 °C) ensures reliable turn-on with standard 5 V microcontroller outputs.

The mounting base is electrically connected to the drain, requiring isolation when heatsink-mounted. Thermal resistance from junction to mounting base is 0.74 K/W, supporting high-power dissipation up to 203 W at T_mb = 25 °C - critical for thermally constrained automotive engine bay environments.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	55 V maximum drain-source voltage - supports 24 V automotive systems with margin against load dump transients.
R_DS(on)	7.1 mΩ typical at V_GS = 5 V, I_D = 25 A, T_j = 25 °C - enables efficient 12 V/24 V load switching with <1.8 W conduction loss at 50 A.
I_D (cont.)	75 A at T_mb = 25 °C - limited by TO-220AB package thermal capacity, not silicon capability.
T_j max	175 °C - allows operation in under-hood environments without derating below ambient extremes.
Q_GD	16 nC typical - determines Miller plateau duration during switching; supports <150 ns turn-off delay with 10 Ω gate resistor.
E_AS	352 mJ non-repetitive avalanche energy - sustains unclamped inductive kickback from solenoids or motors without failure.
R_th(j-mb)	0.74 K/W - defines minimum heatsink requirement: ~0.5 K/W heatsink needed for 100 W steady-state dissipation at ΔT = 74 K.

Pinout & Package

Package: TO-220AB (SOT78), plastic single-ended package with heatsink-mounted mounting base electrically tied to drain terminal. Requires insulated mounting hardware when drain is not at chassis ground.

Pin/Terminal	Circuit Role	Design Meaning
1 (G)	Gate	Control input; accepts 5 V logic-level drive; threshold 1.1–2.0 V ensures TTL/CMOS compatibility.
2 (D)	Drain	Main power output; internally bonded to mounting base - must be electrically isolated from heatsink unless drain referenced to chassis.
3 (S)	Source	Power return path; common reference for gate drive and load current sensing; low-inductance bond wire (7.5 nH).
Mounting Base (mb)	Drain extension	Electrically connected to Pin 2 (D); primary thermal path to heatsink; requires insulating washer if isolation needed.

Key Features

Feature	Design Value
AEC-Q101 qualified	Validated for automotive safety-critical applications including engine control, body electronics, and ADAS power stages.
Logic-level gate drive	Turns fully on with 5 V gate-source voltage - eliminates need for gate driver ICs in MCU-based designs.
175 °C junction rating	Enables uninterrupted operation in high-ambient environments (e.g., near exhaust manifolds or battery compartments).
Low R_DS(on) @ 5 V	7.1 mΩ typical at V_GS = 5 V - reduces conduction loss by >30% vs. standard MOSFETs requiring 10 V drive.
High avalanche energy	352 mJ unclamped E_AS - withstands worst-case inductive flyback without external snubbers in motor/solenoid drivers.

Applications

Automotive Engine Control

Commercial Vehicle Lighting

Use Scenario: Switching fuel injector solenoids and ignition coils in 12 V gasoline/diesel ECUs.

IC Role / Device Role / Timing Role: High-side or low-side power switch handling repetitive 5–20 A pulsed loads with <100 µs switching windows.

Use Value: 175 °C rating prevents thermal shutdown during sustained high-load duty cycles; 352 mJ avalanche ruggedness absorbs coil flyback without clamping diodes.

Use Scenario: Controlling LED headlamps, fog lamps, and brake lights in 24 V heavy-duty trucks.

IC Role / Device Role / Timing Role: Low-side load switch managing 10–40 A steady-state currents with PWM dimming support.

Use Value: 7.1 mΩ R_DS(on) at 5 V drive minimizes heat generation in sealed lamp housings; TO-220AB mountability simplifies mechanical integration.

Industrial Motor Starters

Off-Road Equipment Power Distribution

Use Scenario: Driving 12 V DC brush motors in agricultural machinery and HVAC actuators.

IC Role / Device Role / Timing Role: Bidirectional or unidirectional power switch with reverse recovery handling for inductive back-EMF.

Use Value: Source-drain diode V_SD = 0.85 V at 25 A enables efficient freewheeling; 69 ns trr limits switching losses during commutation.

Use Scenario: Solid-state replacement of mechanical relays in construction equipment battery management modules.

IC Role / Device Role / Timing Role: High-reliability load disconnect switch for 12/24 V auxiliary circuits (winches, hydraulics, PTO).

Use Value: AEC-Q101 qualification ensures long-term reliability under vibration, thermal cycling, and load dump stress per ISO 7637-2.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
STL220N5LF5	60 V V_DS, 220 A peak, 1.8 mΩ R_DS(on) @ 10 V but 3.2 mΩ @ 5 V; DFN8 5×6 mm package.	Higher current density but surface-mount only; lacks mounting base for bolted heatsinking.	Select when PCB space is constrained and thermal interface uses thermal pads; avoid where mechanical mounting or high pulse current is required.
IRF1405ZLPbF	55 V V_DS, 164 A peak, 5.3 mΩ R_DS(on) @ 10 V but 7.8 mΩ @ 5 V; TO-220AB package, no AEC-Q101 qualification.	Same footprint but not automotive-qualified; lower avalanche energy (220 mJ vs. 352 mJ).	Select for cost-sensitive industrial use where AEC-Q101 is not mandated; verify system-level transient immunity separately.

Compared with STL220N5LF5 and IRF1405ZLPbF, the BUK9508-55B uniquely combines AEC-Q101 compliance, 5 V logic-level drive with sub-8 mΩ on-resistance, and integrated drain-to-heatsink thermal path - making it the only choice for production automotive power switches requiring both reliability and simplified thermal design.

Availability

BUK9508-55B is available at Aetrix Electronics and suitable for automotive engine control units, commercial vehicle lighting systems, and industrial motor starters requiring stable component supply across multi-year production cycles.

Supply support for BUK9508-55B 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 global manufacturing and qualification infrastructure.

The BUK9508-55B belongs to NXP's TrenchMOS logic-level power FET product line, engineered specifically for AEC-Q101-compliant automotive power distribution and load switching where 5 V MCU drive, high-temperature operation, and avalanche robustness are mandatory.

FAQ

Is BUK9508-55B suitable for high-frequency PWM motor control?

Yes - with 131 ns t_d(off) and 86 ns t_f at V_GS = 5 V, it supports PWM frequencies up to 20 kHz in brushed DC motor drives. However, its 3960 pF C_iss increases gate drive power above 50 kHz; for >50 kHz operation, consider gate driver buffering or lower-capacitance alternatives.

Can BUK9508-55B be used in high-side configuration?

No - the mounting base is internally connected to the drain (Pin 2), making isolated high-side switching impractical without complex floating gate drive circuitry. It is optimized for low-side switching or source-grounded configurations where the drain connects directly to the load supply rail.

What is the maximum safe operating area (SOA) at 100 °C mounting base temperature?

At T_mb = 100 °C, continuous drain current is derated to 75 A (per Figure 1), and the SOA curve (Figure 3) shows 1 ms pulse capability up to 439 A at V_DS = 10 V. For 100 ms pulses, limit V_DS to ≤25 V and I_D to ≤120 A to stay within thermal limits.

Does BUK9508-55B require a gate resistor for protection?

Yes - a 10 Ω series gate resistor is recommended (per Figure 13 test conditions) to damp ringing, limit peak gate current, and control dV/dt during switching. Lower values (<5 Ω) risk oscillation; higher values (>47 Ω) increase switching losses and thermal stress during transitions.

BUK9508-55B,127 Specifications

Product attributes: Attribute value

Manufacturer:: Nexperia USA Inc.

Series:: TrenchMOS™

Package/Case:: TO-220-3

Packaging:: Tube

Product Status:: Obsolete

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 55 V

Current - Continuous Drain (Id) @ 25°C:: 75A (Tc)

Drive Voltage (Max Rds On, Min Rds On):: 4.5V, 10V

Rds On (Max) @ Id, Vgs:: 7mOhm @ 25A, 10V

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

Gate Charge (Qg) (Max) @ Vgs:: 45 nC @ 5 V

Vgs (Max):: ±15V

Input Capacitance (Ciss) (Max) @ Vds:: 5280 pF @ 25 V

FET Feature:: -

Power Dissipation (Max):: 203W (Tc)

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220AB

BUK9508-55B,127 FAQ

1.How can I place an order for BUK9508-55B,127 through Aetrix?

Please submit a Request for Quotation (RFQ) for BUK9508-55B,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 BUK9508-55B,127 reliable?

The price and inventory of BUK9508-55B,127 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BUK9508-55B,127 is usually 5 days.

3.What payment methods are accepted for BUK9508-55B,127?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BUK9508-55B,127 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BUK9508-55B,127?

BUK9508-55B,127 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BUK9508-55B,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 BUK9508-55B,127?

For technical support, including BUK9508-55B,127 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BUK9508-55B,127 requirements.

6.How does Aetrix verify that BUK9508-55B,127 is sourced from the original manufacturer or authorized distributors?

All BUK9508-55B,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 BUK9508-55B,127 meets industry standards.

7.What is the process for return or replacement of BUK9508-55B,127?

All BUK9508-55B,127 units undergo pre-shipment inspection (PSI). If there is an issue with BUK9508-55B,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 BUK9508-55B,127 part is unused and in its original packaging.

Return procedure for BUK9508-55B,127:

1.Submit a request within 90 days.

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

Tech Hub

2026-09-03 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-01 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…

2026-08-21 What Is an LED Driver? Types, Circuits, Dimming, and Selection

An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…

2026-08-18 Operational Amplifier (Op Amp): Basics, Configurations, Feedback and Applications

Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…

2026-08-14 Jumper Cables: How to Use, Connect and Choose Them Safely

Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…