NXP Semiconductors BUK9520-55,127

Overview

BUK9520-55 from NXP Semiconductors (formerly Philips) is an N-channel enhancement-mode logic-level TrenchMOS™ power transistor in TO220AB (SOT78) package, rated for 55 V drain-source voltage, 52 A DC drain current at 25 °C, and 20 mΩ R_DS(ON) at V_GS = 5 V. It integrates ESD protection up to 2 kV and is designed for automotive and industrial switching applications requiring robust gate drive compatibility with 5 V microcontrollers.

For engineers reviewing the BUK9520-55 datasheet, BUK9520-55 pinout, BUK9520-55 application, or BUK9520-55 equivalent, key selection criteria include its logic-level gate threshold (1–2 V), low on-resistance at 5 V drive, avalanche energy rating (110 mJ), thermal resistance junction-to-mounting-base (1.29 K/W), and integrated reverse diode characteristics (V_SD = 0.95–1.2 V at 25 A).

Technical Context

This discrete MOSFET uses trench-gate technology to achieve low R_DS(ON) while maintaining high avalanche ruggedness and ESD tolerance. Its gate threshold voltage of 1.0–2.0 V at 25 °C enables direct drive from 3.3 V/5 V logic without level-shifting circuitry.

The device features a monolithic zener-protected gate oxide, integral body diode with 47 ns reverse recovery time and 0.15 µC Q_rr, and specified unclamped inductive switching capability up to 110 mJ at 45 A - critical for relay replacement and motor control in harsh environments.

Key Specifications

Pinout & Package

Package: TO220AB (SOT78), plastic envelope with metal tab electrically connected to drain; net mass 2 g; UL94 V0 compliant epoxy.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STP55NF06L and IRFZ44NPBF, the BUK9520-55 delivers superior 5 V drive performance, lower on-resistance at logic-level bias, and certified 2 kV ESD protection - making it the preferred choice for automotive-grade 5 V MCU interfaces where reliability and thermal efficiency are prioritized over raw voltage headroom.

Availability

BUK9520-55 is available at Aetrix Electronics and suitable for automotive body control modules, industrial motor starters, LED lighting drivers, and power supply OR-ing circuits requiring stable component supply and long-term production continuity.

Supply support for BUK9520-55 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

NXP Semiconductors is a global semiconductor leader focused on secure connectivity solutions for automotive, industrial, and IoT applications, with roots in Philips' semiconductor division.

The BUK9520-55 belongs to NXP's TrenchMOS™ logic-level power MOSFET family, engineered specifically for direct microcontroller interfacing in harsh-environment switching applications where low gate drive voltage, high avalanche ruggedness, and integrated ESD protection are mandatory.

FAQ

What is the maximum continuous drain current for BUK9520-55 at 100 °C mounting base temperature?

The BUK9520-55 supports 37 A DC drain current at T_mb = 100 °C, as specified in the Limiting Values table. This derating reflects thermal constraints of the TO220AB package and must be applied in thermal design calculations. The full 52 A rating applies only at 25 °C mounting base temperature. Engineers designing for elevated ambient conditions must verify heatsink performance using R_{th j-mb} = 1.29 K/W and junction temperature limit of 175 °C.

Does BUK9520-55 have a built-in body diode, and what are its key parameters?

Yes, the BUK9520-55 includes an integral body diode with V_SD = 0.95–1.2 V at 25 A and 47 ns reverse recovery time (t_rr). Its Q_rr is 0.15 µC under specified test conditions (IF = 40 A, -dIF/dt = 100 A/µs, V_GS = -10 V, V_R = 30 V). These values enable efficient freewheeling in inductive switching applications without external diodes, though snubbers may still be needed for high-di/dt loads.

Can BUK9520-55 be used in high-frequency PWM applications above 100 kHz?

The BUK9520-55 supports switching frequencies up to several hundred kHz due to its fast turn-off fall time (70–90 ns) and low output capacitance (C_oss = 350–420 pF). However, dynamic losses increase significantly above 100 kHz, especially with resistive gate drive. For optimal efficiency, use gate drivers with ≤10 Ω source/sink impedance and minimize PCB loop inductance. Thermal validation at target frequency and duty cycle is essential before deployment.

What is the gate threshold voltage range of BUK9520-55 across temperature?

The BUK9520-55 has a gate threshold voltage V_GS(th) of 1.0–2.0 V at 25 °C, 0.5–2.3 V at -55 °C, and 0.5–2.0 V at 175 °C. This wide operational window ensures turn-on consistency across automotive temperature extremes. At high temperature, threshold drops - improving conduction but requiring attention to gate drive stability to avoid unintended turn-on during transients.

Is the metal tab of BUK9520-55 electrically isolated from the drain pin?

No - the metal tab of the BUK9520-55 is internally connected to Pin 2 (drain), as confirmed in the PIN CONFIGURATION section. This configuration provides a low-inductance, low-thermal-resistance path for both current conduction and heatsinking. When mounting to a heatsink, electrical isolation (e.g., mica washer + thermal paste) is required unless the heatsink is referenced to drain potential.