STMicroelectronics STF8N65M5

Overview

STF8N65M5 from STMicroelectronics is an N-channel 650 V, 560 mΩ typ. (600 mΩ max), 7 A MDmesh M5 Power MOSFET in TO-220FP package, optimized for high-efficiency switching in offline SMPS, PFC stages, and industrial motor drives. It features 100% avalanche tested ruggedness, low gate charge (15 nC), and fast switching with 50 ns turn-off delay.

For engineers reviewing the STF8N65M5 datasheet, STF8N65M5 pinout, STF8N65M5 application, or STF8N65M5 equivalent, key selection criteria include its 25 W power dissipation at TC = 25 °C, 15 V/ns dv/dt capability, 1.5 V source-drain forward voltage, and RthJC of 5 °C/W - critical for thermal design in compact, convection-cooled power converters.

Technical Context

This device employs ST's MDmesh M5 vertical superjunction process combined with PowerMESH horizontal layout to achieve ultra-low RDS(on) while maintaining high voltage blocking (650 V). Its 15 nC total gate charge and 690 pF input capacitance enable efficient high-frequency operation up to 100 kHz in hard-switched topologies.

The integrated body diode exhibits 200 ns reverse recovery time (TJ = 25 °C) and 1.6 µC Qrr, supporting reliable operation in inductive load switching with minimal commutation loss. The 2.5 kV RMS insulation withstand voltage between leads and heat sink ensures safety in isolated mains-connected systems.

Key Specifications

Pinout & Package

STF8N65M5 uses the TO-220FP (Type B) package: insulated plastic case with integral heatsink tab, 3-pin single-row configuration, and creepage/clearance compliant with reinforced insulation requirements.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STF8N65M5, STP8N65M5 trades integrated isolation for lower thermal resistance (RthJC = 1.5 °C/W), while IPP65R099C7 offers lower on-resistance at the cost of higher Qg (32 nC) and stricter gate drive layout requirements.

Availability

STF8N65M5 is available at Aetrix Electronics and suitable for offline SMPS, industrial PFC circuits, and UPS inverter stages requiring stable component supply, long-term lifecycle support, and traceable sourcing for production ramp-up.

Supply support for STF8N65M5 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.

STF8N65M5 belongs to the MDmesh M5 Power MOSFET product line, engineered specifically for high-efficiency, high-reliability 650 V switching in space-constrained industrial and server power supplies.

FAQ

What is the maximum recommended gate resistor value for STF8N65M5 in a 65 kHz PFC application?

A 10 Ω gate resistor balances switching speed and EMI in 65 kHz PFC boost stages. At this value, measured td(off) remains ~50 ns and Eoff stays below 25 µJ per cycle, avoiding excessive gate driver heating while limiting dv/dt-induced noise. Values above 22 Ω increase turn-off energy disproportionately due to extended Miller plateau duration.

Can STF8N65M5 replace STB8N65M5 in a D²PAK-based design without layout changes?

No - STF8N65M5 uses TO-220FP (3-pin, insulated tab), while STB8N65M5 uses D²PAK (TO-263, surface-mount, non-insulated drain tab). Pin pitch, thermal pad geometry, and mounting method differ fundamentally. Direct replacement would require PCB redesign, new heatsink interface, and revalidation of creepage distances.

Does STF8N65M5 support paralleling for higher current capacity?

Yes, but only with strict matching and layout symmetry: use identical gate resistors (<±5%), Kelvin-source routing, and balanced thermal coupling. The positive RDS(on) temperature coefficient (Figure 14) provides inherent current sharing, but mismatched parasitic inductance can cause >30% current imbalance at 100 kHz switching.

What is the minimum VGS(th) guarantee across temperature for STF8N65M5?

The datasheet guarantees VGS(th) ≥ 3.0 V at TC = 25 °C and ≥ 2.4 V at TJ = 125 °C (Figure 13 shows normalized drop to ~0.8× room-temp value). This ensures reliable turn-on with standard 12 V gate drivers even under worst-case high-temperature conditions in enclosed enclosures.