Nexperia USA Inc. BUK9Y40-55B,115

Overview

BUK9Y40-55B,115 from Nexperia is a logic-level N-channel TrenchMOS FET in LFPAK (SOT669) package, rated for 55 V V_DS, 26 A continuous drain current at T_mb = 25 °C, 34 mΩ R_DS(on) at V_GS = 5 V and T_j = 25 °C, and qualified to AEC-Q101 for automotive critical systems. It serves as a high-reliability power switch in 12 V/24 V load control circuits including solenoid drivers and motor interfaces.

For engineers reviewing the BUK9Y40-55B,115 datasheet, BUK9Y40-55B,115 pinout, BUK9Y40-55B,115 application, or BUK9Y40-55B,115 equivalent, key selection criteria include its 175 °C junction rating, unclamped avalanche energy of 36 mJ, thermal resistance R_th(j-mb) = 2.5 K/W, and compatibility with 5 V logic-level gate drive in space-constrained automotive PCB layouts.

Technical Context

This device implements Nexperia's High-Performance Automotive (HPA) TrenchMOS technology, enabling low R_DS(on) while maintaining robust avalanche ruggedness and stable threshold voltage across -55 °C to +175 °C. Its gate threshold voltage ranges from 1.1 V (typ) to 2.3 V (max) at T_j = -55 °C, ensuring reliable turn-on under cold-cranking conditions.

The integrated source-drain diode exhibits V_SD = 0.85 V (typ) at I_S = 20 A and T_j = 25 °C, supporting freewheeling in inductive loads without external catch diodes. Dynamic parameters-including Q_G(tot) = 11 nC, C_iss = 765 pF (typ), and t_r = 93 ns-support efficient switching in PWM-driven 12 V/24 V power stages up to ~100 kHz.

Key Specifications

Pinout & Package

Package: LFPAK (SOT669), plastic single-ended surface-mounted package with exposed mounting base connected to drain - optimized for thermal performance and mechanical robustness in automotive environments.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STL220N4LF5AG and IRLR024NPBF, BUK9Y40-55B,115 uniquely combines AEC-Q101 qualification, true 5 V logic-level turn-on, and 36 mJ avalanche ruggedness in a thermally optimized LFPAK package - making it the preferred choice for production automotive power switching where reliability and design simplicity are mandatory.

Availability

BUK9Y40-55B,115 is available at Aetrix Electronics and suitable for automotive body control modules, engine management solenoid drivers, and 12 V/24 V brushed DC motor control requiring stable component supply across multi-year vehicle production cycles.

Supply support for BUK9Y40-55B,115 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, logic, and MOSFET solutions - spun off from NXP in 2017 and headquartered in Nijmegen, Netherlands.

The BUK9Y40-55B,115 belongs to Nexperia's Automotive Logic-Level TrenchMOS family, engineered specifically for AEC-Q101-compliant power switching in harsh automotive environments where thermal stability, avalanche robustness, and gate-drive simplicity are essential.

FAQ

Is BUK9Y40-55B,115 suitable for high-side switching configurations?

No - the device is an N-channel MOSFET with source terminals tied internally to the package leads and drain connected to the mounting base. High-side operation would require a P-channel device or an N-channel with isolated gate drive. Its pinout and thermal design are optimized for low-side switching with source grounded to PCB plane.

What is the maximum safe operating area (SOA) at T_mb = 100 °C?

At T_mb = 100 °C, the continuous drain current is derated to 18 A per datasheet limiting values (Table 4). The SOA curve (Figure 4) shows that at V_DS = 10 V, the device supports up to ~15 A DC; at V_DS = 30 V, it supports ~5 A DC - all bounded by R_DS(on) limit line and thermal constraints.

Does BUK9Y40-55B,115 include integrated ESD protection?

Yes - the device features built-in ESD protection rated to ±2 kV HBM (Human Body Model) per JESD22-A114, confirmed in Nexperia's product documentation. This protects against handling damage during assembly but does not replace system-level transient suppression for automotive load-dump or ISO 7637-2 pulses.

Can this MOSFET be paralleled for higher current capacity?

Yes - the device's positive temperature coefficient of R_DS(on) (see Figure 13) ensures inherent current sharing when paralleled. Designers must match gate drive impedance, minimize layout asymmetry, and ensure uniform thermal coupling via shared mounting base or heatsink to avoid thermal runaway.