STMicroelectronics STU8N80K5

Overview

STU8N80K5 from STMicroelectronics is a high-voltage N-channel Power MOSFET based on MDmesh K5 vertical structure, rated for 800 V V_DS, 950 mΩ R_DS(on) max at V_GS = 10 V and 3 A, with 16.5 nC total gate charge and 100% avalanche tested. It delivers ultra-low FoM and Zener-protected gate for hard-switching flyback and resonant converters in industrial power supplies.

For engineers reviewing the STU8N80K5 datasheet, STU8N80K5 pinout, STU8N80K5 application, or STU8N80K5 equivalent, key selection criteria include its 800 V breakdown voltage, 1.14 °C/W R_thJC, 114 mJ E_AS, 4.5 V/ns diode recovery dv/dt rating, and IPAK (TO-251) thermal performance in high-density SMPS designs.

Technical Context

This device employs ST's MDmesh K5 proprietary vertical superjunction architecture to reduce specific on-resistance and gate charge simultaneously. Its Zener-protected gate enables robustness against overvoltage transients without external clamping.

The MOSFET features a fast intrinsic body diode with 300 ns trr at 25 °C and 415 ns at 150 °C, low C_oss (50 pF), and high dv/dt ruggedness (50 V/ns under V_DS ≤ 640 V), making it suitable for ZVS and quasi-resonant topologies requiring reliable unclamped inductive switching.

Key Specifications

Pinout & Package

STU8N80K5 is housed in an IPAK (TO-251) package with exposed drain tab for thermal and electrical connection. The package provides low-profile mounting and high thermal efficiency via direct case-to-heatsink interface.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STP8N80K5, STU8N80K5 trades 0.29 °C/W higher R_thJC for surface-mount compatibility and lower profile; versus FDPF8N80NZ, it adds gate Zener protection and +52% E_AS, directly improving system-level fault tolerance without design rework.

Availability

STU8N80K5 is available at Aetrix Electronics and suitable for industrial flyback SMPS, LLC resonant converter primary switches, and high-voltage DC-DC isolated converters requiring stable component supply and long-lifecycle support.

Supply support for STU8N80K5 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.

STU8N80K5 belongs to the MDmesh K5 high-voltage Power MOSFET product line, engineered specifically for high-efficiency, high-power-density offline power conversion in space-constrained industrial and medical power supplies.

FAQ

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

The STU8N80K5 supports 4 A continuous drain current at T_C = 100 °C, as specified in Table 1 of DS9210 Rev 6. This rating accounts for thermal derating due to junction-to-case resistance (1.14 °C/W) and maximum junction temperature (150 °C), ensuring safe operation without exceeding SOA limits.

Does STU8N80K5 include integrated gate protection?

Yes - STU8N80K5 integrates a gate-source Zener diode rated for ±30 V, confirmed in the "Features" section and validated by gate leakage current (±10 µA at ±20 V) in Table 4. This eliminates the need for external gate clamping in most industrial switching applications.

Can STU8N80K5 replace STP8N80K5 in existing TO-220 layouts?

No - STU8N80K5 uses IPAK (TO-251) packaging with different pinout (G-D-S) and thermal pad layout versus STP8N80K5's TO-220 (G-D-S, non-isolated tab). Direct replacement requires PCB redesign, though both share identical die characteristics and electrical specs.

What is the typical reverse recovery charge (Q_rr) at 150 °C junction temperature?

At T_J = 150 °C, Q_rr is 3.8 µC, per Table 7 footnote and test condition (I_SD = 6 A, di/dt = 100 A/µs, V_DD = 60 V). This value is 27% higher than the 3.0 µC measured at 25 °C, reflecting increased minority-carrier lifetime at elevated temperature.