STMicroelectronics STD5NK40Z-1

Overview

STD5NK40Z-1 from STMicroelectronics is an N-channel 400 V, 1.47 Ω (typ), 3 A Zener-protected SuperMESH™ power MOSFET in IPAK (TO-251) package, optimized for high-speed switching in offline power supplies and PFC stages with 100% avalanche testing and 4.5 V/ns dv/dt capability.

For engineers reviewing the STD5NK40Z-1 datasheet, STD5NK40Z-1 pinout, STD5NK40Z-1 application, or STD5NK40Z-1 equivalent, key selection criteria include R_DS(on) at 10 V gate drive, built-in gate-source Zener protection (±30 V), avalanche energy rating (130 mJ), thermal resistance (2.77 °C/W junction-to-case), and IPAK mechanical compatibility with through-hole PCB mounting.

Technical Context

This device implements ST's SuperMESH™ layout-optimized strip-based PowerMESH™-to simultaneously reduce R_DS(on) and enhance dv/dt immunity. Its gate charge profile (Q_g = 11.7 nC, Q_gd = 5.8 nC) supports fast switching with low drive loss, while integrated back-to-back gate-source Zener diodes (BVGSO = 30 V) eliminate need for external clamping.

The IPAK package delivers 2.77 °C/W junction-to-case thermal resistance and supports 45 W continuous dissipation at T_C = 25 °C. Its source-drain diode exhibits t_rr = 145 ns and Q_rr = 464 nC under 100 A/µs di/dt, enabling robust unclamped inductive switching per Figure 5 test circuit.

Key Specifications

Pinout & Package

STD5NK40Z-1 uses the IPAK (TO-251) package: a 3-lead, through-hole, insulated package with leads bent inward (Gull-wing variant not applicable); case-isolated drain tab requires no insulating washer when mounted to grounded heatsink.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage power switching applications.

Compared with STP5NK40Z and FQP4N40, STD5NK40Z-1 uniquely combines IPAK's compact through-hole mountability, guaranteed avalanche performance, and integrated gate protection-making it optimal for production-grade, safety-certified offline power supplies where board space, reliability, and manufacturability are jointly constrained.

Availability

STD5NK40Z-1 is available at Aetrix Electronics and suitable for AC-DC adapters, active PFC modules, and industrial LED drivers requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for STD5NK40Z-1 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 analog, microcontroller, power, and sensor solutions for automotive, industrial, and consumer markets.

STD5NK40Z-1 belongs to ST's SuperMESH™ high-voltage MOSFET product line, engineered specifically for rugged, high-efficiency switching in offline power conversion-emphasizing avalanche robustness, low gate charge, and Zener-integrated gate protection.

FAQ

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

The maximum continuous drain current (I_D) for STD5NK40Z-1 at T_C = 100 °C is 1.9 A, as specified in the Absolute Maximum Ratings table. This derating reflects thermal limitations of the IPAK package and must be respected in thermal design to avoid exceeding 150 °C junction temperature under sustained load.

Does STD5NK40Z-1 require an external gate resistor for safe operation?

Yes-a gate resistor (typically 4.7 Ω, as used in the datasheet's switching time tests) is required to dampen ringing, limit peak gate current, and control dV/dt-induced shoot-through in half-bridge or synchronous rectifier configurations. The absence of an external resistor risks oscillation and gate oxide overstress despite internal Zener protection.

Can STD5NK40Z-1 replace STD5NK40ZT4 in a DPAK-based design?

No-STD5NK40Z-1 uses IPAK (TO-251) packaging with different lead pitch, body dimensions, and thermal interface geometry versus DPAK (TO-252). Footprint, solder stencil, and heatsink mounting are incompatible; board redesign is required to migrate between these packages, even though the silicon die is identical.

Is the drain tab electrically isolated from the leads in the IPAK package?

No-the drain (Pin 2) is directly connected to the exposed metal tab in STD5NK40Z-1's IPAK package. The tab serves as both thermal path and electrical node; it must be electrically isolated from other circuit nodes unless intentionally tied to drain potential, and cannot be mounted to a grounded heatsink without an insulating pad or shoulder washer.