STMicroelectronics STW15NK50Z

Overview

STW15NK50Z from STMicroelectronics is a Zener-protected N-channel SuperMESH Power MOSFET rated for 500 V drain-source voltage, 340 mΩ maximum R_DS(on), and 14 A continuous drain current at T_C = 25 °C. It features extremely high dv/dt capability (4.5 V/ns), 100% avalanche tested operation, and minimized gate charge (76–106 nC), making it suitable for high-reliability switching power supplies and industrial motor drives.

For engineers reviewing the STW15NK50Z datasheet, STW15NK50Z pinout, STW15NK50Z application, or STW15NK50Z equivalent, key selection criteria include its TO-247 package thermal resistance (R_thJC = 0.78 °C/W), intrinsic capacitance profile (C_iss = 2260 pF, C_oss = 264 pF), and unclamped inductive switching robustness (E_AS = 300 mJ).

Technical Context

This device implements ST's SuperMESH process - an evolution of PowerMESH - delivering reduced on-resistance while preserving high-voltage ruggedness. Its Zener-protected gate structure enables improved ESD tolerance (4 kV HBM) and stable threshold voltage (3.0–4.5 V) across temperature.

The MOSFET supports fast switching with low dynamic losses: typical turn-off delay is 62 ns, fall time is 15 ns, and reverse recovery charge of the integrated body diode is 4.2 µC. Its safe operating area (SOA) is validated up to 56 A pulsed drain current and 14 A repetitive avalanche current.

Key Specifications

Pinout & Package

STW15NK50Z is housed in a TO-247 package with isolated tab (drain-connected), offering superior thermal performance over TO-220 (R_thJC = 0.78 °C/W vs. 0.78 °C/W - identical junction-to-case but lower R_thJA = 50 °C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with STP15NK50Z, STW15NK50Z delivers identical silicon performance in a thermally superior TO-247 package, while FQP15N50 trades ruggedness and gate protection for lower cost - requiring careful SOA validation in any new design.

Availability

STW15NK50Z is available at Aetrix Electronics and suitable for industrial motor drives, server power supplies, and uninterruptible power systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for STW15NK50Z 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 industrial, automotive, and consumer markets.

STW15NK50Z belongs to the SuperMESH Power MOSFET product line, engineered specifically for high-efficiency, high-reliability switching in offline power conversion and motor control applications demanding 500 V voltage class and rugged transient handling.

FAQ

Is STW15NK50Z pin-compatible with STP15NK50Z?

Yes - both share identical pinout (G-D-S) and terminal assignment in their respective packages: STW15NK50Z uses TO-247 (pin 1 = G, pin 2 = D/tab, pin 3 = S), while STP15NK50Z uses TO-220 (same numbering). Mechanical mounting differs, but PCB layout for gate/source routing remains directly transferable.

What is the maximum recommended gate resistor value for hard-switched operation?

For 100–200 kHz hard-switched applications, a gate resistor of 10–22 Ω is recommended to limit peak gate current while maintaining <62 ns turn-off delay. Lower values (≤5 Ω) may cause ringing due to low gate impedance; higher values (>47 Ω) increase switching losses beyond acceptable levels per the 76–106 nC Q_g spec.

Does STW15NK50Z require external gate clamping in standard applications?

No - the integrated Zener protection between gate and source (±30 V rating) eliminates need for external TVS diodes in typical gate-drive circuits. External clamping is only advised in systems with >100 V/ns common-mode transients or where gate-loop inductance exceeds 20 nH.

Can STW15NK50Z replace STB15NK50Z in existing designs?

No - STB15NK50Z was discontinued and removed from DS2858 Rev 5 (Feb 2026). STW15NK50Z is not a drop-in replacement: STB15NK50Z used TO-220FP package with different thermal and mechanical characteristics. Redesign of heatsinking and layout is required for migration.