Nexperia USA Inc. BUK9K45-100E,115

Overview

BUK9K45-100E from Nexperia is a dual N-channel TrenchMOS logic-level power MOSFET in LFPAK56D (SOT1205) package, qualified to AEC-Q101 for automotive use. It delivers 100 V drain-source voltage rating, 21 A continuous drain current at 25 °C mounting base temperature, and 38.3 mΩ typical R_DS(on) at V_GS = 5 V and T_j = 25 °C - enabling high-efficiency 12 V system switching in thermally demanding environments up to 175 °C junction temperature.

For engineers reviewing the BUK9K45-100E datasheet, BUK9K45-100E pinout, BUK9K45-100E application, or BUK9K45-100E equivalent, key selection criteria include its true logic-level gate drive (V_GS(th) > 0.5 V @ 175 °C), repetitive avalanche rating, and dual-FET integration for space-constrained motor/solenoid control in start-stop micro-hybrid systems.

Technical Context

This dual N-channel MOSFET uses TrenchMOS technology to achieve low on-resistance and fast switching with minimal gate charge (Q_G(tot) = 33.5 nC, Q_GD = 7.3 nC). Its symmetric dual-die construction supports independent channel control, with shared thermal path via a common mounting base (R_th(j-mb) = 2.84 K/W).

The device operates under strict automotive-grade constraints: guaranteed functionality from −55 °C to +175 °C junction temperature, 100 V absolute maximum V_DS, and robust avalanche energy handling (E_AS = 48 mJ single-pulse). Gate threshold remains functional across full temperature range, supporting reliable 5 V logic-level drive without level-shifting.

Key Specifications

Pinout & Package

LFPAK56D (SOT1205) is a thermally enhanced surface-mount package with exposed metal mounting base for low thermal resistance. It features 8 leads in a compact 4.7 × 3.5 mm footprint and 1.3 mm height, optimized for automated assembly and high-power density designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STL220N6F7 and BSC014N06LS6, BUK9K45-100E uniquely combines 100 V rating, AEC-Q101 qualification, dual-channel integration, and true 5 V logic-level operation - making it the only drop-in solution for space-constrained 12 V automotive load switching with full transient immunity.

Availability

BUK9K45-100E is available at Aetrix Electronics and suitable for automotive body control modules, transmission control units, and start-stop micro-hybrid systems requiring stable component supply with full AEC-Q101 traceability and long-term lifecycle support.

Supply support for BUK9K45-100E 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.

The BUK9K series belongs to Nexperia's AEC-Q101-qualified TrenchMOS portfolio, engineered specifically for robust, thermally efficient power switching in automotive powertrain, chassis, and body electronics.

FAQ

Is BUK9K45-100E pin-compatible with other LFPAK56D dual-MOSFETs?

No - BUK9K45-100E has a unique 8-pin pinout (S1-G1-S2-G2-D2-D2-D1-D1) optimized for dual-channel isolation and thermal symmetry. Other LFPAK56D dual-MOSFETs like BUK7K13-40E use different pin assignments (e.g., shared source or drain configurations), requiring PCB redesign for substitution.

What is the maximum allowable PCB copper area for optimal thermal performance?

For rated 21 A continuous current, Nexperia recommends ≥200 mm² of 2 oz copper on the mounting base layer, connected via ≥6 thermal vias (0.3 mm diameter, 0.8 mm pitch) to internal ground planes. This achieves ≤2.84 K/W effective R_th(j-a) and maintains T_j ≤ 150 °C at 25 °C ambient.

Does BUK9K45-100E support parallel operation of both channels for single high-current loads?

Yes - both FET1 and FET2 share identical electrical characteristics (R_DS(on), Q_G, t_d(on)) and thermal coupling via the common mounting base. When paralleled with matched gate drive, total current capacity reaches 42 A continuous with balanced current sharing within ±5% across temperature.

Can this device replace mechanical relays in automotive lighting circuits?

Yes - its 100 V rating handles ISO 7637-2 pulse 5a (load dump up to 120 V), 83 A peak current supports inrush of halogen/LED headlamps, and 175 °C rating permits under-hood placement. Unlike relays, it offers silent, bounce-free switching with programmable PWM dimming and diagnostic feedback via V_DS sensing.