STMicroelectronics STB14NK50ZT4

Overview

STB14NK50ZT4 from STMicroelectronics is a Zener-protected N-channel SuperMESH Power MOSFET rated for 500 V drain-source voltage, 340 mΩ typical R_DS(on), and 14 A continuous drain current at T_C = 25 °C in D²PAK (TO-263) package. It delivers high dv/dt capability (4.5 V/ns), 100% avalanche tested operation, and gate charge minimized to 69 nC (typ.), enabling robust switching in offline SMPS and industrial motor drives.

For engineers reviewing the STB14NK50ZT4 datasheet, STB14NK50ZT4 pinout, STB14NK50ZT4 application, or STB14NK50ZT4 equivalent, key selection criteria include its 500 V breakdown voltage, 12 A repetitive avalanche current, 400 mJ single-pulse avalanche energy, 2000 pF input capacitance, and thermal resistance of 0.83 °C/W (junction-to-case) - all critical for high-reliability high-voltage power conversion designs.

Technical Context

This device implements ST's SuperMESH technology - an optimized evolution of PowerMESH - delivering reduced on-resistance while maintaining superior ruggedness. Its Zener-protected gate structure ensures ±30 V gate-source rating and 4 kV HBM ESD immunity, eliminating external gate protection in many applications.

The MOSFET supports unclamped inductive switching with validated safe operating area up to 12 A/500 V, and features fast diode recovery (t_rr = 470 ns, Q_rr = 3.1 µC) with 13.2 A peak reverse recovery current - essential for hard-switched PFC and flyback converters where diode behavior directly impacts efficiency and EMI.

Key Specifications

Pinout & Package

D²PAK (TO-263) package: surface-mount, isolated tab (drain), 3-pin configuration with standard footprint per Figure 24 in DS2637 Rev 4. Thermal pad soldered to PCB copper for enhanced heat transfer.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STP14NK50Z and STW14NK50Z, STB14NK50ZT4 uniquely balances SMT manufacturability, thermal performance (0.83 °C/W), and compact D²PAK footprint - making it optimal for space-constrained, high-power-density industrial power supplies.

Availability

STB14NK50ZT4 is available at Aetrix Electronics and suitable for AC-DC power supplies, industrial motor drives, LED street lighting drivers, and PLC output stages requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for STB14NK50ZT4 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.

STB14NK50ZT4 belongs to the SuperMESH Power MOSFET product line - engineered specifically for high-efficiency, high-reliability switching in 400–600 V industrial power conversion systems where avalanche ruggedness and thermal performance are non-negotiable.

FAQ

What is the maximum continuous drain current at 100 °C case temperature?

The STB14NK50ZT4 supports 7.6 A continuous drain current at T_C = 100 °C, as specified in Table 1 of DS2637 Rev 4. This derating reflects thermal limits of the D²PAK package and ensures safe operation within the SOA boundary under sustained high-temperature conditions.

Does this MOSFET require external gate protection?

No - the STB14NK50ZT4 integrates Zener protection between gate and source, rated for ±30 V, and has been tested to 4 kV HBM ESD. External gate resistors or TVS diodes are unnecessary in standard 500 V applications, though a 10–47 Ω series gate resistor is still recommended for ringing suppression.

How does its avalanche capability compare to standard MOSFETs?

STB14NK50ZT4 is 100% factory-tested for repetitive avalanche at 12 A and delivers 400 mJ single-pulse energy - exceeding typical industrial MOSFETs not rated for unclamped inductive switching. This enables snubberless designs and eliminates reliance on external clamping components in flyback and resonant converters.

Can it replace STP14NK50Z in existing TO-220 designs?

No - STB14NK50ZT4 uses D²PAK (TO-263) packaging and is not pin-compatible with TO-220. While electrically identical, the change requires PCB redesign, new stencil, and requalification of thermal performance due to different R_thJC (0.83 vs. 3.6 °C/W) and mounting method (surface-mount vs. through-hole).