STMicroelectronics STF21N65M5

Overview

STF21N65M5 from STMicroelectronics is an N-channel 650 V, 17 A Power MOSFET in TO-220FP package, featuring 150 mΩ typical R_DS(on), 15 V/ns dv/dt capability, and 100% avalanche tested performance. It leverages MDmesh M5 vertical process technology for high-efficiency switching in offline SMPS, PFC stages, and industrial motor drives.

For engineers reviewing the STF21N65M5 datasheet, STF21N65M5 pinout, STF21N65M5 application, or STF21N65M5 equivalent, key selection criteria include its 650 V V_DSS, 179 mΩ max R_DS(on), 68 A pulsed drain current, 125 W power dissipation at T_C = 25 °C, and 4.17 °C/W junction-to-case thermal resistance - all critical for high-voltage, high-reliability power conversion designs.

Technical Context

This MOSFET integrates ST's MDmesh M5 silicon with PowerMESH layout to achieve ultra-low conduction loss while maintaining robust fast-switching behavior. Its 150 mΩ typ. R_DS(on) at V_GS = 10 V and 8.5 A enables high-efficiency operation in continuous conduction mode (CCM) PFC and resonant LLC topologies.

The device supports high dv/dt immunity (15 V/ns) and exhibits low gate charge (50 nC total, 23 nC Q_gd) for reduced switching losses. Its integrated body diode delivers 294 ns reverse recovery time at 17 A and 100 A/µs di/dt, enabling hard-switched operation without external snubbers in many applications.

Key Specifications

Pinout & Package

STF21N65M5 uses the TO-220FP (Full-Pak) package: insulated plastic case with integral heat sink tab, enabling direct mounting to PCB without insulating washers. Pin 1 = Gate, Pin 2 = Drain (Tab), Pin 3 = Source.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STP21N65M5, STF21N65M5 trades 3.17 °C/W higher junction-to-case thermal resistance for simplified mounting and enhanced safety compliance; versus IPW65R041CFD7, it offers plug-in compatibility with existing silicon MOSFET gate drivers and lower system-level design risk at the cost of ~30% higher conduction loss.

Availability

STF21N65M5 is available at Aetrix Electronics and suitable for industrial motor drives, server power supplies, photovoltaic inverters, and EV onboard chargers requiring stable component supply across multi-year production cycles.

Supply support for STF21N65M5 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.

STF21N65M5 belongs to the MDmesh™ M5 high-voltage Power MOSFET product line, engineered specifically for high-efficiency, high-reliability AC-DC and DC-DC conversion in industrial and renewable energy systems.

FAQ

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

The STF21N65M5 supports 10.7 A continuous drain current at T_C = 100 °C, as specified in Table 1 of DS6116 Rev 5. This rating reflects thermal derating due to reduced heat transfer efficiency at elevated case temperatures and must be validated against actual PCB layout and heatsink performance.

Does STF21N65M5 require a negative gate voltage for reliable turn-off?

No. STF21N65M5 is a standard N-channel enhancement-mode MOSFET with V_GS(th) of 3–5 V and ±25 V gate-source voltage rating. It operates reliably with 0 V turn-off and +10 V to +15 V turn-on; negative gate bias is not required or recommended.

Can STF21N65M5 replace STP21N65M5 in an existing TO-220 footprint?

No - STF21N65M5 uses TO-220FP (full-pack) with insulated tab and different lead spacing, while STP21N65M5 uses standard TO-220 with conductive tab. Mechanical and thermal mounting differ significantly; PCB footprint and heatsink interface must be redesigned.

Is the body diode suitable for synchronous rectification in a flyback converter?

The integrated body diode has 294 ns t_rr and 4 µC Q_rr at 25 °C, making it usable in quasi-resonant flyback designs up to ~100 kHz. However, for high-frequency synchronous rectification (>150 kHz), a dedicated Schottky or GaN FET is preferred to minimize recovery loss and EMI.