STMicroelectronics STF20N95K5

Overview

STF20N95K5 from STMicroelectronics is a high-voltage N-channel Power MOSFET using MDmesh K5 technology, designed for primary-side switching in offline SMPS, PFC stages, and industrial HV DC-DC converters. It delivers 950 V V_(BR)DSS, 275 mΩ typ. R_DS(on) at V_GS = 10 V, and 17.5 A continuous drain current at T_C = 25 °C, with Zener-protected gate and 100% avalanche tested reliability.

For engineers reviewing the STF20N95K5 datasheet, STF20N95K5 pinout, STF20N95K5 application, or STF20N95K5 equivalent, key selection criteria include its ultra-low Q_g (48 nC), FoM-optimized R_DS(on) × Q_g, 6 V/ns diode recovery dv/dt capability, and TO-220FP package thermal resistance (R_thJC = 3.1 °C/W).

Technical Context

This device implements a proprietary vertical MDmesh K5 structure to minimize conduction and switching losses simultaneously. Its 950 V breakdown voltage supports universal AC input designs up to 400 V DC bus, while the low 275 mΩ R_DS(on) reduces conduction loss in high-current PFC boost stages.

The integrated Zener gate protection enables robust operation under transient overvoltage conditions, and the 100% unclamped inductive avalanche testing (E_AS = 200 mJ at T_J = 25 °C) ensures ruggedness in hard-switched topologies without external snubbers.

Key Specifications

Pinout & Package

STF20N95K5 uses the TO-220FP (Full-Pak) package: insulated plastic case with integral heat sink tab, enabling direct mounting to heatsinks without insulating washers. The package provides 3.1 °C/W junction-to-case thermal resistance and 62.5 °C/W junction-to-ambient (on standard FR-4).

Key Features

Applications

Equivalent & Alternatives

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

Compared with STF20N95K5, STP20N95K5 offers superior thermal conduction but adds insulation complexity, while IXTH20N95L2 trades gate protection for slightly lower Q_g and higher avalanche energy-making STF20N95K5 optimal for cost-sensitive, space-constrained industrial SMPS requiring plug-and-play ruggedness.

Availability

STF20N95K5 is available at Aetrix Electronics and suitable for industrial motor drives, telecom rectifier modules, medical imaging power supplies, and EV charging station auxiliary supplies requiring stable component supply across multi-year production cycles.

Supply support for STF20N95K5 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.

The STF20N95K5 belongs to ST's MDmesh K5 high-voltage Power MOSFET family, engineered specifically for high-efficiency, high-power-density offline power conversion in industrial and telecom infrastructure.

FAQ

What is the maximum safe operating frequency for STF20N95K5 in a PFC boost converter?

STF20N95K5 supports up to 200 kHz operation in continuous conduction mode (CCM) PFC, based on its 48 nC Q_g, 32.5 nC Q_gd, and 18 ns t_r/18 ns t_f. At 150 kHz, gate drive loss remains below 0.8 W with a 10 Ω resistor, keeping junction temperature within 150 °C limit under typical 17.5 A peak current conditions.

Does STF20N95K5 require external gate protection in standard SMPS designs?

No. STF20N95K5 integrates a monolithic Zener diode between gate and source rated for ±30 V, providing sufficient protection against typical gate driver overshoot and ESD events per IEC 61000-4-2 Level 2. External gate resistors (≥10 Ω) are still required for ringing suppression, but discrete Zener clamps are unnecessary.

How does the TO-220FP package affect PCB layout versus TO-220?

The TO-220FP's insulated tab eliminates need for thermal pads or insulating washers, simplifying heatsink mounting and reducing assembly steps. However, its 3.1 °C/W R_thJC is higher than TO-220's 0.5 °C/W, so PCB copper area must be increased by ~30% to maintain equivalent thermal performance in natural convection scenarios.

Can STF20N95K5 replace STW20N95K5 in a TO-247-based design?

Electrically identical, but mechanical replacement requires redesign: STF20N95K5's TO-220FP has different footprint, mounting hole pattern, and lower thermal conductivity. Direct substitution is not recommended unless thermal simulation confirms junction temperature stays ≤135 °C under worst-case load, given the 6.2× higher R_thJC.