Nexperia USA Inc. BUK9Y09-40B,115

Overview

BUK9Y09-40B from Nexperia is an AEC-Q101 qualified N-channel TrenchMOS logic-level power MOSFET in LFPAK (SOT669) package, rated for 40 V V_DS, 75 A continuous drain current at 25 °C mounting base temperature, and 175 °C maximum junction temperature. It delivers 6.9 mΩ R_DS(on) at V_GS = 5 V and T_j = 25 °C, enabling efficient 12 V automotive load switching in thermally constrained environments.

For engineers reviewing the BUK9Y09-40B datasheet, BUK9Y09-40B pinout, BUK9Y09-40B application, or BUK9Y09-40B equivalent, this device is selected for high-current, logic-level gate-driven power switching where automotive qualification, avalanche ruggedness (146 mJ), and low thermal resistance (1.42 K/W j-mb) are critical design requirements.

Technical Context

This MOSFET uses TrenchMOS technology to achieve low on-resistance with logic-level gate drive compatibility (V_GS(th) = 1.25–2.15 V at 25 °C). Its gate threshold remains functional down to 0.5 V at 175 °C, supporting stable operation across full automotive temperature range.

The device features a robust unclamped inductive switching capability (EDS(AL)S = 146 mJ), integrated source-drain diode with 40 ns reverse recovery time, and optimized dynamic parameters including Q_GD = 11 nC and C_iss = 2150–2866 pF - all specified under standardized test conditions per IEC 60134.

Key Specifications

Pinout & Package

Package: LFPAK (SOT669) - plastic single-ended surface-mounted package with exposed mounting base connected to drain, optimized for high-current, low-inductance, and high-thermal-performance applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STL220N4F7AG and IRL8721PBF, the BUK9Y09-40B uniquely balances logic-level drive, AEC-Q101 qualification, 40 V rating, and LFPAK thermal performance - making it optimal for space- and reliability-critical automotive power switching where gate simplicity and under-hood operation are mandatory.

Availability

BUK9Y09-40B is available at Aetrix Electronics and suitable for automotive body control modules, 12 V DC motor drives, and LED lighting power stages requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for BUK9Y09-40B 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, with leadership in automotive-qualified components and advanced packaging.

The BUK9Y series belongs to Nexperia's TrenchMOS logic-level automotive power MOSFET product line, engineered specifically for robust, high-efficiency 12 V load switching in harsh automotive environments.

FAQ

Is BUK9Y09-40B suitable for high-frequency PWM switching?

Yes - with t_f = 83 ns, t_r = 92 ns, and Q_GD = 11 nC, the device supports PWM frequencies up to several hundred kHz in motor and LED dimming applications. Its low C_iss and optimized gate charge profile minimize switching losses and EMI generation when paired with appropriate gate resistance.

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

At T_mb = 100 °C, the continuous drain current is derated to 53 A (per Table 4), and the SOA curve (Figure 4) shows safe operation up to V_DS = 10 V at 53 A DC, or up to V_DS = 30 V at pulsed currents ≤100 A for 10 ms - enabling reliable operation in transient-heavy automotive loads.

Does BUK9Y09-40B require a gate resistor for MCU-driven operation?

A gate resistor is recommended - typically 10 Ω - to dampen ringing and limit peak gate current during switching. The device's Q_G(tot) = 30 nC and low C_iss allow clean transitions even with 3.3 V or 5 V MCU outputs, but external resistance ensures robust EMI control and prevents shoot-through in bridge configurations.

How does the source-drain diode performance compare to discrete Schottky diodes?

The integrated body diode has V_SD = 0.85–1.2 V and t_rr = 40 ns - higher forward drop and slower recovery than most Schottky diodes. It is sufficient for low-frequency freewheeling (e.g., <50 kHz motor control) but not ideal for high-frequency synchronous rectification; external Schottky diodes remain preferred for efficiency-critical designs.