STMicroelectronics STP8NK80Z

Overview

STP8NK80Z from STMicroelectronics is a Zener-protected N-channel 800 V, 1.3 Ω typ. (1.5 Ω max.), 6.2 A SuperMESH Power MOSFET in TO-220FP package, designed for high-voltage switching in offline SMPS, lighting ballasts, and AC motor controls where robust dv/dt immunity and avalanche ruggedness are critical.

For engineers reviewing the STP8NK80Z datasheet, STP8NK80Z pinout, STP8NK80Z application, or STP8NK80Z equivalent, this device requires attention to gate charge (46 nC), output capacitance (143 pF), reverse recovery performance (460 ns trr, 2.99 µC Qrr), and thermal resistance (RthJC = 4.2 °C/W) when designing hard-switched flyback or resonant converters.

Technical Context

This MOSFET employs ST's SuperMESH process-optimized from PowerMESH-to reduce RDS(on) while maintaining high V(BR)DSS (800 V min.) and exceptional dv/dt capability (4.5 V/ns). Its intrinsic Zener protection across gate-source eliminates external clamping in high-noise environments.

The device features low Crss (27 pF) and Coss eq. (58 pF), enabling efficient operation in high-frequency quasi-resonant topologies. Its 100% avalanche-tested rating (EAS = 300 mJ) ensures reliability under unclamped inductive switching stress.

Key Specifications

Pinout & Package

STP8NK80Z is supplied in TO-220FP (Full-Pak) package: insulated plastic case with electrically isolated tab, enabling direct mounting to heatsink without insulator kit. Pin 1 = Gate, Pin 2 = Drain (tab-connected), Pin 3 = Source.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STP8NK80Z, STP8NK80ZFP offers superior thermal performance but demands electrical isolation, while STW8NK80Z provides maximum creepage and ruggedness at the cost of board area-choice depends on thermal path constraints, safety spacing, and mechanical environment.

Availability

STP8NK80Z is available at Aetrix Electronics and suitable for offline SMPS, HID electronic ballasts, and industrial motor starters requiring stable component supply, long-lifecycle support, and traceable sourcing for Class B industrial equipment.

Supply support for STP8NK80Z 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, delivering automotive, industrial, and power discrete solutions with vertical manufacturing and application-focused design centers.

This device belongs to ST's SuperMESH Power MOSFET product line, engineered specifically for high-voltage, high-ruggedness switching in energy-efficient power conversion systems operating up to 800 V DC bus.

FAQ

Is STP8NK80Z suitable for use in a 230 VAC-fed flyback converter?

Yes. With 800 V V_DS, it safely withstands the 650 V peak rectified voltage plus margin in universal-input designs. Its 300 mJ EAS rating handles leakage inductance energy without snubber redesign, and 1.5 Ω R_DS(on) keeps conduction loss under 1.2 W at 6.2 A, making it ideal for 50–100 W flyback topologies.

What is the gate threshold voltage range, and how does it affect drive design?

V_GS(th) is specified from 3.0 V to 4.5 V (typ. 3.75 V) at 100 µA ID. This tight range ensures consistent turn-on behavior across temperature and lot variation. Drive circuits must deliver ≥10 V to fully enhance the channel and achieve rated R_DS(on); 5 V logic-level drivers are insufficient.

Does STP8NK80Z require an external gate resistor, and what value is recommended?

Yes-an external gate resistor is mandatory to control dV/dt and suppress oscillation. For typical 65 kHz flyback operation, a 4.7 Ω resistor (as used in ST's reference test circuit) balances switching speed and EMI. Lower values increase switching loss; higher values raise turn-on time and Q_g-related losses.

Can STP8NK80Z replace older STP7NK80Z devices in existing designs?

Yes-STP8NK80Z is a direct upgrade: identical pinout, same 800 V rating, lower R_DS(on) (1.5 Ω vs 1.8 Ω), and improved dv/dt immunity (4.5 V/ns vs 3.5 V/ns). No layout changes are needed; thermal and gate drive designs benefit from reduced losses and enhanced ruggedness.