NXP Semiconductors BUK127-50GT,115

Overview

BUK127-50GT,115 from NXP Semiconductors (formerly Philips) is a monolithic logic-level TOPFET power MOSFET with integrated temperature and overload protection, rated for 50 V drain-source voltage, 2.1 A continuous drain current, and 200 mΩ R_DS(ON) at T_mb = 25 °C. It serves as a protected high-side switch in automotive lamp and solenoid control circuits.

For engineers reviewing the BUK127-50GT,115 datasheet, BUK127-50GT,115 pinout, BUK127-50GT,115 application, or BUK127-50GT,115 equivalent, key selection criteria include its 5 V logic-compatible input, latch-reset protection architecture, SOT223 thermal resistance (R_{th j-sp} = 12–18 K/W), clamping energy rating (EDSM = 100 mJ), and direct microcontroller drivability without external level-shifting.

Technical Context

The BUK127-50GT,115 integrates a TrenchMOS output stage with on-chip current-trip and overtemperature protection circuits powered from the input pin. Protection triggers at ≥4 A drain current (ID(TO)) or ≥150 °C junction temperature (Tj(TO)), latching off until input voltage drops below 2.5 V for ≥100 µs.

It features built-in ESD protection (2 kV HBM), overvoltage clamping active above 50 V (V_(CL)DSS ≤ 70 V at ID = 200 mA), and reverse diode forward voltage of 0.83–1.1 V at IS = 2 A - optimized for inductive load switching in 12 V automotive systems.

Key Specifications

Pinout & Package

Package: SOT223 (SC-73), surface-mount plastic package with exposed drain tab for thermal conduction to PCB copper.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar protected high-side switch applications.

Compared with STL225N5LF5AG and BTS3028SDL, the BUK127-50GT,115 offers self-contained analog protection with minimal external components, making it optimal for cost-sensitive, space-constrained automotive switches where deterministic latch-reset behavior is preferred over programmable diagnostics.

Availability

BUK127-50GT,115 is available at Aetrix Electronics and suitable for automotive lamp control, 12 V solenoid actuation, and heater element switching requiring stable component supply across production lifecycles.

Supply support for BUK127-50GT,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

NXP Semiconductors is a global semiconductor leader focused on secure connectivity solutions for automotive, industrial, and IoT applications.

The BUK127-50GT,115 belongs to NXP's legacy TOPFET family - designed specifically for robust, single-chip protected switching in 12 V automotive subsystems where reliability under overload and thermal stress is critical.

FAQ

What is the maximum continuous drain current rating for BUK127-50GT,115?

The BUK127-50GT,115 has a continuous drain current rating of 2.1 A at ambient temperature (T_a = 25 °C) with proper PCB heatsinking. This value decreases with rising board temperature and is limited by thermal resistance (R_{th j-a} = 70 K/W on specified FR4 layout). Derating curves in the datasheet must be applied for operation above 25 °C ambient.

Does BUK127-50GT,115 require an external pull-down resistor on the input pin?

No, the BUK127-50GT,115 does not require an external pull-down resistor. Its input stage includes internal biasing that ensures the device remains off when the input is floating or disconnected. However, for noise immunity in automotive environments, a 10–100 kΩ pull-down to ground is recommended in production designs using the BUK127-50GT,115.

How does the overload protection reset mechanism work in BUK127-50GT,115?

The BUK127-50GT,115 enters latched-off state during overload or overtemperature events and remains off until the input voltage falls below 2.5 V for at least 100 µs (typical latch reset time t_lr = 10–100 µs). This reset condition must be met before the device can be re-enabled - ensuring fault conditions are fully cleared before resuming operation.

Can BUK127-50GT,115 safely switch inductive loads like relays or solenoids?

Yes, the BUK127-50GT,115 is explicitly designed for inductive load switching. Its integrated overvoltage clamping circuit actively turns on the MOSFET when drain voltage exceeds 50 V, absorbing up to 100 mJ (non-repetitive) of inductive energy. This eliminates the need for external flyback diodes in many 12 V automotive applications using the BUK127-50GT,115.

What is the thermal resistance from junction to solder point (R_{th j-sp}) for BUK127-50GT,115?

The junction-to-solder-point thermal resistance (R_{th j-sp}) for BUK127-50GT,115 is specified as 12–18 K/W. This parameter reflects heat transfer efficiency from the silicon die to the PCB solder joint through the exposed drain tab in the SOT223 package - critical for estimating junction temperature rise under load when using the BUK127-50GT,115 in thermally constrained layouts.