STMicroelectronics STFI34N65M5

Overview

STFI34N65M5 from STMicroelectronics is an N-channel 650 V, 0.09 Ω typ. R_DS(on), 28 A MDmesh™ V Power MOSFET in I2PAKFP (TO-281) package. It delivers high dv/dt ruggedness (50 V/ns), 100% avalanche tested performance, and low gate charge (62.5 nC), enabling high-efficiency switching in offline SMPS and PFC stages.

For engineers reviewing the STFI34N65M5 datasheet, STFI34N65M5 pinout, STFI34N65M5 application, or STFI34N65M5 equivalent, key selection criteria include its 650 V V_DS, 0.09 Ω R_DS(on) at 10 V_GS, 150 °C T_jmax, 3.57 °C/W R_thj-case, and I2PAKFP thermal-mechanical profile for high-power density designs.

Technical Context

This device employs ST's MDmesh™ V vertical silicon process combined with PowerMESH™ horizontal layout to achieve industry-leading R_DS(on) × area efficiency. Its 650 V breakdown voltage (V_(BR)DSS) and 710 V V_DS @ T_jmax support robust operation in universal-input AC-DC converters.

The MOSFET features optimized capacitance profile (C_iss = 2700 pF, C_oss = 75 pF, C_rss = 6.3 pF) and fast switching (t_d(v) = 59 ns, t_r(v) = 8.7 ns), enabling high-frequency operation while maintaining low E_on/E_off losses under 400 V bus conditions.

Key Specifications

Pinout & Package

The STFI34N65M5 is housed in an I2PAKFP (TO-281) package - a full-packaged variant of I2PAK with insulated tab, rated for 2500 V_RMS isolation between leads and heatsink. Its 3-pin configuration supports high-current drain-source paths with low-inductance source return.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STW34N65M5 and IPP65R099C7, the STFI34N65M5 uniquely combines I2PAKFP's 2500 V_RMS isolation, 50 V/ns dv/dt rating, and 100% avalanche testing-making it the sole option for compact, insulated, high-reliability 650 V switching where mechanical clearance and transient immunity are constrained.

Availability

STFI34N65M5 is available at Aetrix Electronics and suitable for server power supplies, telecom rectifiers, solar microinverters, and industrial motor drives requiring stable component supply across multi-year production cycles.

Supply support for STFI34N65M5 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 and discrete power devices for industrial, automotive, and consumer markets.

The MDmesh™ V product line targets high-efficiency, high-power-density AC-DC and DC-DC conversion, specifically engineered to replace older 600 V MOSFET generations in space- and thermal-constrained offline power systems.

FAQ

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

The STFI34N65M5 supports 17.7 A continuous drain current at T_C = 100 °C, as specified in Table 2 of the datasheet. This derating reflects thermal limits imposed by its 3.57 °C/W R_thj-case and 150 °C maximum junction temperature, requiring appropriate heatsinking for sustained operation above 25 °C ambient.

Does the I2PAKFP package provide electrical isolation between leads and heatsink?

Yes-the I2PAKFP package provides 2500 V_RMS insulation withstand voltage from all three leads to external heatsink (t = 1 s, T_C = 25 °C), per Table 2. This eliminates need for insulating pads or sleeves in most industrial and telecom applications, simplifying mechanical assembly and improving thermal reliability.

How does the 100% avalanche testing impact system-level reliability?

Each STFI34N65M5 unit undergoes single-pulse avalanche stress test to guarantee E_AS ≥ 510 mJ and I_AR ≥ 7 A. This ensures consistent energy-handling capability during unclamped inductive switching events-reducing field failure risk in PFC, flyback, and LLC circuits where snubbers are omitted for cost or efficiency reasons.

Can this MOSFET be used in synchronous rectification applications?

No-the STFI34N65M5 is optimized as a high-voltage primary-side switch, not a low-V_DS synchronous rectifier. Its body diode has 1.5 V forward voltage and 350 ns reverse recovery time, which is unsuitable for secondary-side rectification where low V_F and fast t_rr are mandatory. Use dedicated SR controllers with logic-level MOSFETs instead.