Nexperia USA Inc. BUK9Y38-100E,115

Overview

BUK9Y38-100E from Nexperia is an AEC-Q101 qualified N-channel logic-level MOSFET in LFPAK56 (SOT669) package, rated for 100 V V_DS, 38 mΩ R_DS(on) at V_GS = 5 V and T_j = 25 °C, with 175 °C junction temperature rating and repetitive avalanche capability - deployed in automotive transmission control and 48 V power switching circuits.

For engineers reviewing the BUK9Y38-100E datasheet, BUK9Y38-100E pinout, BUK9Y38-100E application, or BUK9Y38-100E equivalent, this device is selected for thermally demanding 12–48 V automotive loads requiring true logic-level gate drive (V_GS(th) > 0.5 V at 175 °C), low conduction loss, and robust avalanche energy handling (45.1 mJ).

Technical Context

This MOSFET uses TrenchMOS technology to achieve low R_DS(on) while maintaining high voltage blocking and thermal resilience. Its gate threshold voltage remains functional up to 175 °C, enabling stable operation in under-hood environments without external level-shifting circuitry.

The LFPAK56 package integrates a thermally optimized mounting base directly connected to the drain, delivering R_th(j-mb) = 1.58 K/W and supporting 94.9 W total power dissipation at T_mb = 25 °C - critical for sustained motor and solenoid drive duty cycles.

Key Specifications

Pinout & Package

LFPAK56 (SOT669) is a 4-lead surface-mount plastic package with exposed mounting base (drain-connected) for low thermal resistance and high power density. The package measures 4.41 × 3.62 × 1.20 mm and features gull-wing leads compatible with standard reflow processes.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STL220N6F7 and IRF3205PBF, BUK9Y38-100E uniquely combines 100 V rating, true 5 V logic-level operation, AEC-Q101 qualification, and 175 °C thermal capability - making it the only drop-in solution for next-generation 48 V automotive power distribution without gate driver overhead or derating penalties.

Availability

BUK9Y38-100E is available at Aetrix Electronics and suitable for automotive transmission control, 48 V mild hybrid interfaces, LED headlamp matrix drivers, and electric power steering motor phases requiring stable component supply across extended temperature and lifetime requirements.

Supply support for BUK9Y38-100E 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, ESD protection, and logic families.

This device belongs to Nexperia's LFPAK automotive MOSFET product line, engineered specifically for high-efficiency, high-temperature power switching in engine control units, ADAS actuators, and 12–48 V vehicle electrification systems.

FAQ

Is BUK9Y38-100E suitable for high-frequency PWM motor control above 50 kHz?

Yes - with 10 ns turn-on delay, 18 ns rise time, and 8.3 nC gate-drain charge, it supports clean switching up to 100 kHz in brushed DC motor drivers. However, gate drive strength must exceed 1 A peak to minimize switching losses, and PCB layout must minimize source inductance using the three-source-pin configuration.

Can BUK9Y38-100E replace older SO-8 MOSFETs in existing automotive designs?

Yes, but only with mechanical and thermal validation: LFPAK56 has identical footprint pitch to Power-SO8 but thicker profile (1.2 mm vs. 1.75 mm) and drain-connected mounting base. Thermal interface must be redesigned to utilize the mb pad; electrical pinout matches SO-8 (G-D-S-S), but pin 4 is gate, not drain.

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

At T_mb = 100 °C, continuous drain current is derated to 21.3 A (per datasheet Fig. 1), and SOA is limited by R_DS(on) heating and transient thermal impedance. For 10 ms pulses, peak current remains ≤120 A at V_DS ≤ 20 V, but must stay below the curve defined in Fig. 4 to avoid second breakdown.

Does the source-drain body diode support synchronous rectification in buck converters?

Yes - with 0.78 V forward voltage at 5 A and 31 ns reverse recovery time, it performs adequately in low-duty-cycle 48 V buck stages. However, Q_r = 44 nC limits efficiency at high frequencies (>200 kHz); external Schottky diode parallel may be needed for optimal light-load performance.