STMicroelectronics STL8N80K5

Overview

STL8N80K5 from STMicroelectronics is an N-channel 800 V, 0.80 Ω typ. R_DS(on), 4.5 A Zener-protected SuperMESH™ 5 Power MOSFET in PowerFLAT™ 5x6 VHV package. It delivers ultra-low gate charge (16.5 nC), 100% avalanche-tested ruggedness, and integrated back-to-back gate-source Zener protection-designed for high-efficiency, high-voltage switching in offline SMPS and industrial AC-DC converters.

For engineers reviewing the STL8N80K5 datasheet, STL8N80K5 pinout, STL8N80K5 application, or STL8N80K5 equivalent, key selection criteria include its 800 V V_(BR)DSS, 0.95 Ω max R_DS(on) at 10 V_GS, 4.5 A continuous drain current, Zener-protected gate, and PowerFLAT™ 5x6 VHV thermal performance (R_thj-case = 3 °C/W).

Technical Context

This device employs ST's SuperMESH™ 5 vertical structure to achieve industry-leading figure-of-merit (FOM) with R_DS(on) × Q_g = 15.7 Ω·nC. Its Zener-protected gate integrates dual back-to-back diodes rated at ±30 V_(BR)GSO, eliminating external gate protection components while maintaining ESD robustness and transient immunity.

The MOSFET features ultra-fast switching (t_d(on) = 12 ns, t_f = 20 ns) and low output capacitance (C_oss = 50 pF, C_o(er) = 24 pF), enabling high-frequency operation up to 100 kHz in hard-switched topologies. Its 114 mJ single-pulse avalanche energy (E_AS) and 50 V/ns MOSFET dv/dt ruggedness support reliable unclamped inductive switching.

Key Specifications

Pinout & Package

STL8N80K5 is housed in a surface-mount PowerFLAT™ 5x6 VHV package with exposed drain pad for thermal and electrical performance. The package features 8 terminals: pins 1–3 and 5–8 are drain-connected, pin 4 is gate, and pins 1–3 are source-connected (dual-side source bonding).

Key Features

Applications

Equivalent & Alternatives

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

Compared with STL8N80K5, STW20NK80Z offers higher current and lower R_DS(on) but sacrifices Zener protection and surface-mount compatibility, while FDPF8N80NZ trades away ruggedness and integration for lower unit cost-making STL8N80K5 optimal for compact, surge-immune, high-reliability 4–6 A SMPS designs.

Availability

STL8N80K5 is available at Aetrix Electronics and suitable for industrial AC-DC adapters, LED streetlight drivers, and telecom rectifier modules requiring stable component supply, long-term lifecycle assurance, and consistent parametric performance across production batches.

Supply support for STL8N80K5 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, MCU, power, and sensor solutions for industrial, automotive, and consumer markets.

This device belongs to ST's SuperMESH™ 5 high-voltage MOSFET product line, engineered specifically for high-efficiency, high-reliability offline power conversion in space-constrained applications demanding ruggedness, low loss, and simplified protection.

FAQ

What is the maximum gate-source voltage rating for STL8N80K5?

The absolute maximum gate-source voltage is ±30 V, enforced by integrated back-to-back Zener diodes. This eliminates the need for external gate protection components and ensures safe operation during layout-induced voltage spikes or ESD events. The typical Zener breakdown occurs at exactly ±30 V with ±1 mA test current, as confirmed in Table 8 of the datasheet.

Can STL8N80K5 be used in zero-voltage switching (ZVS) topologies?

Yes-its ultra-low C_oss (50 pF) and C_rss (1 pF), combined with 16.5 nC total gate charge, enable efficient ZVS operation in LLC resonant and active-clamp forward converters. The device's 300 ns reverse recovery time (t_rr) at 150 °C and low Q_rr (3.8 µC) further reduce switching losses during soft-commutation transitions.

Does STL8N80K5 require a heatsink in typical applications?

No external heatsink is required when mounted on a 1-inch² FR-4 board with 2 oz copper, as its R_thj-amb is 59 °C/W and R_thj-case is 3 °C/W. At 4.5 A continuous drain current and 0.95 Ω R_DS(on), junction temperature remains below 125 °C with natural convection-enabling compact, fanless designs in adapters and LED drivers.

How does the Zener protection affect gate drive design?

The integrated ±30 V gate-source Zeners allow direct connection to standard 12–15 V gate drivers without external clamping. During negative transients (e.g., Miller-induced undershoot), the cathode-connected Zener conducts to limit V_GS to –30 V; during positive spikes, the anode-connected Zener clamps to +30 V-preserving gate oxide integrity and simplifying PCB layout.