STMicroelectronics STD3N80K5

Overview

STD3N80K5 from STMicroelectronics is a high-voltage N-channel Power MOSFET based on MDmesh K5 technology, rated for 800 V V_DS, 2.8 Ω typ. R_DS(on) at V_GS = 10 V, and 2.5 A continuous drain current at T_C = 25 °C. It features ultra-low gate charge (9.5 nC), 100% avalanche tested operation, and Zener-protected gate, targeting high-efficiency switching in offline SMPS and industrial power supplies.

For engineers reviewing the STD3N80K5 datasheet, STD3N80K5 pinout, STD3N80K5 application, or STD3N80K5 equivalent, key selection criteria include its 800 V breakdown voltage, 2.8 Ω typical on-resistance, 9.5 nC total gate charge, 65 mJ single-pulse avalanche energy, and IPAK (TO-251) thermal resistance of 2.08 °C/W junction-to-case.

Technical Context

This device employs ST's proprietary MDmesh K5 vertical structure to achieve industry-leading R_DS(on) × area and FoM. Its 800 V V_(BR)DSS and 50 V/ns MOSFET dv/dt ruggedness support robust operation in high-voltage flyback and resonant converters.

The integrated Zener-protected gate ensures ±30 V V_GS tolerance, while the source-drain diode delivers 2.5 A continuous current with 265 ns reverse recovery time at T_J = 25 °C - enabling self-commutated topologies without external freewheeling diodes.

Key Specifications

Pinout & Package

STD3N80K5 is housed in an IPAK (TO-251) package with exposed drain tab for thermal and electrical connection. The package complies with ECOPACK environmental standards and provides 2.08 °C/W junction-to-case thermal resistance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STP3N80K5, STD3N80K5 trades 0.58 °C/W higher junction-to-case thermal resistance for compact IPAK packaging and lower assembly cost; versus FQP3N80, it delivers 22% lower R_DS(on), 32% less gate charge, and guaranteed avalanche ruggedness - directly improving efficiency and reliability in demanding switching topologies.

Availability

STD3N80K5 is available at Aetrix Electronics and suitable for AC-DC power supplies, industrial relay drivers, and high-voltage LED drivers requiring stable component supply across multi-year production cycles.

Supply support for STD3N80K5 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.

STD3N80K5 belongs to ST's MDmesh K5 high-voltage Power MOSFET product line, engineered specifically for high-efficiency, high-density offline power conversion in space-constrained industrial and lighting applications.

FAQ

What is the maximum safe operating voltage for STD3N80K5 in continuous DC operation?

The absolute maximum drain-source voltage (V_DS) is 800 V, with V_(BR)DSS guaranteed at 800 V minimum when tested at I_D = 1 mA and V_GS = 0 V. For reliable long-term operation, ST recommends derating to ≤720 V DC in designs with voltage transients or poor regulation margin.

Does STD3N80K5 require an external gate resistor for stability?

Yes - a gate resistor (typically 4.7–10 Ω) is required to dampen ringing caused by gate loop inductance and intrinsic gate resistance (R_g = 15.5 Ω). Without it, overshoot exceeding ±30 V may trigger the internal Zener clamp repeatedly, increasing gate drive loss and risk of cumulative degradation.

Can STD3N80K5 replace older STD3NK80Z devices in existing designs?

No - STD3NK80Z uses Zener-clamped SuperMESH technology with different R_DS(on) (4.5 Ω max), Q_g (15 nC), and gate threshold (2–4 V). Swapping requires revalidation of gate drive strength, SOA margins, and avalanche performance due to fundamental process and parameter differences.

Is the source-drain diode suitable for continuous freewheeling in synchronous rectification?

No - the body diode has 265 ns trr and 1.2 µC Q_rr at 25 °C, making it unsuitable for high-frequency synchronous rectification. It is designed for occasional commutation (e.g., flyback snubbing or relay flyback), not sustained bidirectional conduction; external Schottky diodes are recommended for >50 kHz freewheeling paths.