STMicroelectronics STP15NK50Z

Overview

STP15NK50Z from STMicroelectronics is a Zener-protected N-channel SuperMESH Power MOSFET in TO-220 package, rated for 500 V drain-source voltage, 340 mΩ max R_DS(on), and 14 A continuous drain current at T_C = 25 °C. It delivers high dv/dt capability (4.5 V/ns), 100% avalanche tested performance, and low gate charge (76–106 nC) for robust switching in offline SMPS and motor control.

For engineers reviewing the STP15NK50Z datasheet, STP15NK50Z pinout, STP15NK50Z application, or STP15NK50Z equivalent, this device supports high-reliability industrial power conversion where unclamped inductive energy handling, ESD immunity (4 kV HBM), and thermal stability across –50 to 150 °C junction range are critical selection criteria.

Technical Context

This MOSFET employs ST's SuperMESH process - an evolution of PowerMESH - to reduce on-resistance while maintaining high voltage ruggedness and fast switching dynamics. Its 2260 pF input capacitance and 64 pF reverse transfer capacitance enable predictable gate drive behavior under high-speed hard-switching conditions.

The device integrates a built-in Zener diode between gate and source for overvoltage protection, supports repetitive avalanche operation up to 14 A, and features a 300 mJ single-pulse avalanche energy rating at T_J = 25 °C - enabling reliable operation in flyback and resonant converters without external snubbers.

Key Specifications

Pinout & Package

STP15NK50Z uses a TO-220 package with isolated tab (drain-connected). The three leads are arranged in standard linear configuration: Pin 1 = Gate, Pin 2 = Drain (tab), Pin 3 = Source.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STW15NK50Z, STP15NK50Z trades thermal headroom for compactness and cost; versus IPP60R190C6, it sacrifices some conduction loss for guaranteed avalanche ruggedness and integrated gate protection - making it more suitable for cost-sensitive, reliability-critical industrial SMPS.

Availability

STP15NK50Z is available at Aetrix Electronics and suitable for offline AC/DC adapters, industrial motor controls, and lighting ballasts requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for STP15NK50Z 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power devices, sensors, and analog ICs for automotive, industrial, and consumer markets.

This device belongs to ST's SuperMESH Power MOSFET product line - engineered specifically for high-voltage, medium-power switching applications demanding ruggedness, low gate charge, and consistent avalanche performance in harsh electrical environments.

FAQ

What is the maximum recommended gate resistor value for STP15NK50Z in a 65 kHz flyback design?

A 10 Ω to 22 Ω gate resistor is typical for 65 kHz operation with a 1-A peak driver, balancing switching speed (to minimize overlap loss) and EMI control. At 76–106 nC total gate charge, 15 Ω yields ~1.6 µs turn-on time - sufficient to stay within SOA limits while avoiding excessive ringing from parasitic inductance.

Can STP15NK50Z replace STP16NF50 in an existing design?

No - STP16NF50 has 500 V rating but 16 A/0.3 Ω specs and different gate threshold (2–4 V vs 3–4.5 V). STP15NK50Z's higher R_DS(on) and tighter V_GS(th) range may cause inconsistent turn-on in gate-drive circuits designed for NF50's lower threshold, risking thermal runaway under partial enhancement.

Is the drain tab electrically isolated in the TO-220 package?

No - the metal tab is internally connected to the drain terminal (Pin 2). When mounted to a heatsink, electrical isolation (e.g., mica washer + thermal paste) is mandatory unless the heatsink is referenced to high-voltage rail. This is confirmed in Figure 21 and Table 8 of DS2858 Rev 5.

Does STP15NK50Z support paralleling for higher current capacity?

Yes - its positive temperature coefficient for R_DS(on) (see Figure 11) enables stable current sharing when paralleled with identical units. However, matched gate resistors (<±5% tolerance) and symmetrical PCB layout (equal trace inductance) are required to prevent dynamic imbalance during switching transitions.