STMicroelectronics STW31N65M5

Overview

STW31N65M5 from STMicroelectronics is an N-channel 650 V, 124 mΩ typ. (148 mΩ max), 22 A MDmesh M5 Power MOSFET in TO-247 package, designed for high-efficiency hard-switching and resonant topologies in industrial power supplies, PFC stages, and solar inverters.

For engineers reviewing the STW31N65M5 datasheet, STW31N65M5 pinout, STW31N65M5 application, or STW31N65M5 equivalent, key selection criteria include avalanche ruggedness (5 A repetitive), low gate charge (45 nC), fast switching (td(v) = 46 ns), and 100% avalanche-tested reliability under unclamped inductive load conditions.

Technical Context

This device implements ST's MDmesh M5 vertical superjunction process combined with PowerMESH horizontal layout, delivering ultra-low R_DS(on) while maintaining high voltage blocking (650 V) and robust dv/dt immunity (50 V/ns MOSFET ruggedness). Its optimized capacitance profile (C_iss = 1865 pF, C_oss = 45 pF) supports high-frequency operation up to 100 kHz in ZVS/ZCS circuits.

The integrated body diode features low forward voltage (V_SD = 1.5 V @ 22 A) and controlled reverse recovery (Q_rr = 5–6 μC, t_rr = 336–406 ns), reducing switching losses and EMI in bridge-leg configurations. Thermal resistance R_thJC is 0.83 °C/W, enabling high-power density designs with minimal heatsinking.

Key Specifications

Pinout & Package

STW31N65M5 uses the TO-247 package - a through-hole, isolated-tab power package with 3 leads and 1 electrically active metal tab (drain-connected). It provides superior thermal performance over TO-220/TO-220FP variants and mechanical compatibility with industry-standard heatsink mounting hardware.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STW31N65M5, IPW65R090CFD7 offers lower conduction loss and enhanced gate control at the expense of layout complexity, while IXTH30N65X2 trades marginal R_DS(on) increase for significantly softer diode recovery-critical in transformer-isolated topologies where voltage overshoot must be minimized.

Availability

STW31N65M5 is available at Aetrix Electronics and suitable for industrial power supplies, solar inverters, motor drives, and high-voltage PFC modules requiring stable component supply across multi-year production cycles.

Supply support for STW31N65M5 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 analog, digital, and mixed-signal ICs for automotive, industrial, and power applications.

STW31N65M5 belongs to the MDmesh™ M5 Power MOSFET product line, engineered specifically for high-efficiency, high-reliability 600–650 V switching in industrial power conversion systems demanding low loss, avalanche robustness, and long-term stability.

FAQ

What is the maximum junction temperature and how does it affect continuous current rating?

The STW31N65M5 has a rated operating junction temperature range of –55 °C to 150 °C. At T_C = 100 °C, its continuous drain current drops to 13.9 A due to thermal derating-this reflects the 0.83 °C/W R_thJC limiting power dissipation to ~41 W. Designers must ensure heatsink interface resistance and ambient temperature keep T_J ≤ 150 °C under worst-case load and airflow conditions.

Is STW31N65M5 suitable for use in zero-voltage switching (ZVS) resonant converters?

Yes-its low C_oss (45 pF) and Co(er) (43 pF), combined with 1865 pF C_iss, provide predictable capacitive turn-on behavior essential for ZVS operation. Measured t_d(v) = 46 ns and t_r(v) = 8 ns confirm fast, controllable voltage rise, enabling reliable soft-switching down to 50 kHz in LLC and phase-shifted full-bridge topologies.

Does the TO-247 package require electrical isolation from the heatsink?

Yes-the metal tab is internally connected to the drain (Pin 2), so direct mounting to a grounded heatsink creates a short circuit. An electrically isolating but thermally conductive interface (e.g., silicone pad or mica washer with thermal grease) is mandatory unless the heatsink is floated at drain potential, which is uncommon in grounded-system designs.

How does the body diode performance compare to discrete ultrafast diodes in bridge configurations?

The integrated body diode delivers V_SD = 1.5 V @ 22 A and Q_rr = 5–6 μC, outperforming many 600 V ultrafast diodes (e.g., MUR1560: Q_rr ≈ 10 μC) in recovery charge-but with higher forward drop than Schottky alternatives. Its controlled t_rr and low I_RRM (30–31 A) minimize voltage spikes during commutation, reducing snubber requirements in hard-switched H-bridges.