Nexperia USA Inc. BUK9Y3R5-40E,115

Overview

BUK9Y3R5-40E from Nexperia is an AEC-Q101-qualified N-channel logic-level MOSFET in LFPAK56 (SOT669) package, rated for 40 V V_DS, 3.8 mΩ R_DS(on) at V_GS = 5 V and T_j = 25 °C, and 175 °C junction operation. It delivers 100 A continuous drain current at T_mb = 25 °C and supports ultra-high-performance power switching in 12 V automotive systems including transmission control and solenoid drivers.

For engineers reviewing the BUK9Y3R5-40E datasheet, BUK9Y3R5-40E pinout, BUK9Y3R5-40E application, or BUK9Y3R5-40E equivalent, key selection criteria include its true logic-level gate (V_GS(th) > 0.5 V at 175 °C), repetitive avalanche rating, 0.9 K/W junction-to-mounting-base thermal resistance, and LFPAK56 package's high-power density and PCB thermal efficiency.

Technical Context

This MOSFET employs TrenchMOS technology to achieve low R_DS(on) with robust switching performance: Q_GD = 8.6 nC and t_f = 29.5 ns enable fast, controlled turn-off in high-frequency PWM applications. Its gate threshold remains functional up to 175 °C, ensuring reliable drive in thermally demanding under-hood environments.

The device integrates a source-drain diode with V_SD = 0.82–1.2 V at I_S = 25 A and T_j = 25 °C, and supports unclamped single-pulse avalanche energy E_AS = 135 mJ - critical for inductive load commutation without external snubbers in motor and solenoid circuits.

Key Specifications

Pinout & Package

LFPAK56 (SOT669) is a 4-lead surface-mount plastic package with exposed mounting base connected to drain, optimized for high-current automotive power switching. Its low-profile design (max height 1.20 mm) and large copper area support efficient PCB heat spreading.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STL220N4F7AG and NTMFS4C09NT1G, BUK9Y3R5-40E uniquely guarantees logic-level operation (V_GS(th) ≥ 0.5 V) at 175 °C and includes repetitive avalanche rating - making it the only option qualified for high-reliability, thermally aggressive automotive power switching where gate drive voltage headroom is limited.

Availability

BUK9Y3R5-40E is available at Aetrix Electronics and suitable for automotive transmission control, engine start-stop solenoid drivers, and electric power steering motor phases requiring stable component supply, long-term lifecycle assurance, and AEC-Q101-compliant traceability.

Supply support for BUK9Y3R5-40E 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 ICs.

The BUK9Y series is Nexperia's AEC-Q101-qualified logic-level MOSFET product line designed specifically for thermally demanding 12 V automotive power switching applications - emphasizing ruggedness, low R_DS(on), and guaranteed high-temperature gate functionality.

FAQ

Is BUK9Y3R5-40E suitable for high-side switching configurations?

No - the LFPAK56 package connects the mounting base to drain, and pins 1–3 are source-only. High-side switching requires isolated gate drive and careful level-shifting; this device is optimized for low-side or half-bridge low-side use where source is referenced to ground or a known potential. Its pinout does not support bootstrap or floating gate drive without external isolation.

What is the maximum allowable PCB copper area for the mounting base?

The mounting base (drain) has no strict upper limit on copper area - larger thermal pads improve heat dissipation. Nexperia recommends minimum 200 mm² of 2 oz copper connected via ≥6 thermal vias (0.3 mm diameter, spaced ≤2 mm apart) to internal or backside ground planes. Excessive copper beyond thermal needs does not degrade electrical performance.

Does BUK9Y3R5-40E require a gate resistor for automotive PWM applications?

Yes - a gate resistor (typically 5–22 Ω) is required to control dV/dt, suppress ringing, and limit peak gate current. The datasheet specifies t_d(off) = 43.2 ns and t_f = 29.5 ns with R_G(ext) = 5 Ω; increasing resistance slows switching to reduce EMI but increases switching losses. Layout parasitics also influence optimal value.

Can BUK9Y3R5-40E replace older BUK9Y3R7-40E in existing designs?

Yes - both share identical LFPAK56 package, pinout, and AEC-Q101 qualification. BUK9Y3R5-40E offers lower R_DS(on) (3.8 mΩ vs. 3.7 mΩ typical, 4.0 mΩ max for BUK9Y3R7-40E), improved thermal resistance (0.9 K/W vs. 1.0 K/W), and tighter V_GS(th) specification at high temperature. No layout or drive changes are needed for drop-in replacement.