STMicroelectronics STF8NM50N

Overview

STF8NM50N from STMicroelectronics is an N-channel 500 V, 730 mΩ (typ), 5 A MDmesh™ II Power MOSFET in TO-220FP package. It delivers low gate charge (14 nC), low input capacitance (364 pF), and 100% avalanche-tested ruggedness for high-efficiency offline SMPS, PFC stages, and industrial motor drives.

For engineers reviewing the STF8NM50N datasheet, STF8NM50N pinout, STF8NM50N application, or STF8NM50N equivalent, key selection criteria include its 15 V/ns dv/dt capability, 140 mJ single-pulse avalanche energy, 6.25 °C/W junction-to-case thermal resistance, and integrated body diode with 187 ns reverse recovery time at 150 °C.

Technical Context

This MOSFET employs ST's second-generation MDmesh vertical strip architecture to minimize R_DS(on) and gate charge simultaneously. Its optimized cell layout enables high-voltage operation while maintaining fast switching (t_d(off) = 25 ns, t_f = 8.8 ns) and low C_iss/C_rss ratio (364 pF / 1.2 pF), reducing Miller effect and improving hard-switching robustness.

The device integrates a fast-recovery body diode (Q_rr = 1.3 µC, t_rr = 187 ns at T_J = 25 °C) and supports unclamped inductive switching up to 2 A repetitive avalanche current. Its 2.5 kV RMS insulation withstand voltage between leads and heat sink enables safe use in isolated high-side configurations.

Key Specifications

Pinout & Package

TO-220FP (Full-Pak) package with insulated tab: thermally conductive but electrically isolated mounting surface rated for 2.5 kV RMS. Compact footprint (L3 = 28.6–30.6 mm) and low-profile height (H = 10.0–10.4 mm) support dense PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STP8NM50 and FDPF18N50, STF8NM50N uniquely combines insulated-tab packaging, low Q_g, and MDmesh™ II efficiency-making it optimal for safety-critical, high-density, high-frequency offline converters where thermal and electrical isolation are co-required.

Availability

STF8NM50N is available at Aetrix Electronics and suitable for industrial motor drives, server PSU PFC stages, and offline SMPS flyback converters requiring stable component supply and long-term lifecycle assurance.

Supply support for STF8NM50N 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, designing and manufacturing microcontrollers, power devices, sensors, and analog ICs for automotive, industrial, and consumer markets.

The MDmesh™ power MOSFET product line targets high-efficiency AC-DC and DC-DC conversion, emphasizing low R_DS(on), low gate charge, and rugged avalanche performance for demanding industrial and computing power applications.

FAQ

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

The STF8NM50N supports 3 A continuous drain current at T_C = 100 °C, as specified in Table 1 (ID at T_C = 100 °C). This derating reflects thermal limits of the TO-220FP package and ensures safe operation within the SOA boundary at elevated temperatures.

Does the STF8NM50N have an integrated ESD protection diode on the gate?

No. The device does not integrate gate ESD protection; its gate-body leakage current (±100 nA at ±25 V) and V_GS absolute maximum rating (±25 V) indicate standard gate oxide robustness. External gate protection (e.g., Zener clamp) is recommended in high-noise industrial environments.

Can STF8NM50N be used in synchronous rectification topologies?

No. As an N-channel high-side switch with non-optimized body diode forward voltage (V_SD = 1.5 V at 5 A), it is unsuitable for synchronous rectification. Its design prioritizes high-voltage blocking and avalanche ruggedness-not low V_F or bidirectional conduction.

What is the safe operating area (SOA) limitation at 100 µs pulse width?

At 100 µs pulse width and T_J = 150 °C, the SOA is limited by R_DS(on) to approximately 4 A at 200 V V_DS, per Figure 1. This reflects the device's ability to sustain short-duration overload without thermal runaway or secondary breakdown.