STMicroelectronics STF18N65M2

Overview

STF18N65M2 from STMicroelectronics is an N-channel 650 V, 12 A MDmesh M2 Power MOSFET in TO-220FP package, featuring 275 mΩ typ. R_DS(on), 20 nC total gate charge, and 100% avalanche tested. It delivers low turn-off switching losses and excellent C_OSS profile for high-efficiency flyback and PFC converters in industrial SMPS.

For engineers reviewing the STF18N65M2 datasheet, STF18N65M2 pinout, STF18N65M2 application, or STF18N65M2 equivalent, key selection criteria include its 50 V/ns dv/dt ruggedness, 2.5 kV insulation withstand voltage, Zener-protected gate, and optimized SOA for continuous conduction mode (CCM) operation at 100 °C case temperature.

Technical Context

This MOSFET employs ST's MDmesh M2 strip layout and enhanced vertical structure to simultaneously reduce R_DS(on) and output capacitance. Its C_OSS,eq of 175 pF (0–520 V) and low Q_gd/Q_gs ratio (8.5 nC / 3.6 nC) enable fast, soft-switching behavior in hard-switched topologies.

The device integrates a robust body diode with 331 ns trr (T_J = 25 °C) and 4.6 µC Q_rr (T_J = 150 °C), supporting quasi-resonant and LLC designs where diode recovery stress must be minimized. Its 5 °C/W R_thJC supports thermal design up to 25 W dissipation at T_C = 25 °C.

Key Specifications

Pinout & Package

TO-220FP (Type B) package: isolated tab, vertical mounting, 3-pin through-hole format with integrated heatsink interface. Pin 1 = Gate (G), Pin 2 = Drain (D), Pin 3 = Source (S). Tab is electrically connected to Drain.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STP18N65M2 and IPP65R380C7, STF18N65M2 uniquely combines reinforced isolation (2.5 kV), superior R_DS(on)/Q_g trade-off, and MDmesh M2's flat C_OSS curve-making it optimal for safety-critical, space-constrained industrial SMPS where thermal headroom and EMI control are critical.

Availability

STF18N65M2 is available at Aetrix Electronics and suitable for industrial AC-DC power supplies, server rectifiers, and UPS inverter stages requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for STF18N65M2 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.

The MDmesh M2 product line targets high-efficiency, high-reliability power conversion systems-specifically engineered for 650 V applications demanding low R_DS(on), fast switching, and robust avalanche performance in compact form factors.

FAQ

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

The STF18N65M2 supports 8 A continuous drain current at T_C = 100 °C, as specified in Table 1 of DS10577 Rev 3. This rating reflects thermal derating due to junction-to-case thermal resistance (5 °C/W) and maximum junction temperature limit (150 °C), ensuring safe operation in convection-cooled industrial enclosures.

Does the device include integrated gate protection?

Yes-the STF18N65M2 features an integrated Zener diode between gate and source, clamping gate-source voltage to ±25 V. This eliminates the need for external gate protection components in standard gate drive circuits, reducing BOM count and PCB area while maintaining robustness against ESD and transient overvoltage.

How does the C_OSS,eq value differ from standard C_OSS?

C_OSS,eq (175 pF) is defined as the constant capacitance that yields the same charging time as the actual nonlinear C_OSS when V_DS rises from 0 to 520 V (80% of 650 V). Unlike typical C_OSS measured at fixed 100 V, C_OSS,eq directly correlates with turn-on energy loss in hard-switched applications, making it more useful for efficiency estimation.

Can this MOSFET replace older STF18N65M in existing designs?

Yes-STF18N65M2 is a direct drop-in replacement for STF18N65M, offering identical pinout, package, and voltage/current ratings, but with improved R_DS(on) (275 mΩ typ. vs. 330 mΩ typ.), lower Q_g, and enhanced dv/dt ruggedness (50 V/ns vs. 35 V/ns). No layout or drive circuit changes are required to realize measurable efficiency gains.