STMicroelectronics STF6N90K5

Overview

STF6N90K5 from STMicroelectronics is a high-voltage N-channel Power MOSFET using MDmesh™ K5 technology, rated for 900 V V_DS, 0.91 Ω typ. R_DS(on) at 10 V V_GS, and 6 A continuous drain current at T_C = 25 °C. It features ultra-low gate charge (11 nC), 100% avalanche tested operation, and integrated Zener-protected gate-source diodes. It serves as a primary switching device in offline SMPS, PFC stages, and industrial AC-DC converters.

For engineers reviewing the STF6N90K5 datasheet, STF6N90K5 pinout, STF6N90K5 application, or STF6N90K5 equivalent, key selection criteria include its 900 V breakdown voltage, 5 °C/W junction-to-case thermal resistance, TO-220FP insulated package with 2500 V_RMS isolation, and verified unclamped inductive switching capability up to 210 mJ single-pulse avalanche energy.

Technical Context

This MOSFET employs ST's proprietary vertical MDmesh™ K5 structure to minimize conduction and switching losses simultaneously. Its 342 pF input capacitance (C_iss) and low 1.2 pF reverse transfer capacitance (C_rss) enable fast, controllable switching with minimal Miller effect.

The device integrates back-to-back gate-source Zener diodes rated at ±30 V, eliminating external ESD protection components. Its 342 ns typical reverse recovery time (T_rr) and 3.13 µC Q_rr support efficient operation in hard-switched inductive loads without snubber dependency.

Key Specifications

Pinout & Package

STF6N90K5 is housed in a TO-220FP (Full-Pak) package with insulated tab, enabling direct mounting to a common heatsink without electrical isolation hardware. The plastic body isolates all three leads from the heatsink interface.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STW6N90K5 and FCH90N90F, STF6N90K5 uniquely combines insulated packaging, ultra-low Q_g, and guaranteed avalanche ruggedness-making it optimal for cost-sensitive, space-constrained, and safety-critical offline power stages where gate protection and simplified thermal design are prioritized.

Availability

STF6N90K5 is available at Aetrix Electronics and suitable for industrial AC-DC power supplies, telecom rectifiers, and PFC boost stages requiring stable component supply and long-term lifecycle assurance.

Supply support for STF6N90K5 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, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

The MDmesh™ K5 product line targets high-efficiency, high-power-density switching applications-specifically engineered to replace older planar MOSFETs in 600–900 V offline power conversion with superior R_DS(on) × Q_g figure of merit.

FAQ

Is STF6N90K5 suitable for use without external gate protection?

Yes. STF6N90K5 integrates back-to-back Zener diodes between gate and source with ±30 V breakdown voltage, providing inherent ESD and overvoltage protection. This eliminates the need for external gate clamping components in standard gate drive configurations with ≤20 V drive rails.

What is the maximum recommended gate resistor value for reliable switching?

A 10 Ω gate resistor is validated for clean 12.4 ns turn-on delay and 15.5 ns fall time at 450 V V_DD and 3 A I_D. Values above 22 Ω increase switching losses significantly; below 4.7 Ω may cause ringing due to layout parasitics. Layout-dependent optimization is advised for >100 kHz operation.

Can STF6N90K5 replace STP6N90K5 in existing designs?

No. STP6N90K5 uses TO-220 (non-insulated) package with exposed drain tab, while STF6N90K5 uses TO-220FP with insulated tab and 2500 V_RMS isolation. Mechanical mounting, thermal interface, and safety clearance must be revalidated; electrical specs are identical, but system-level insulation requirements differ.

Does STF6N90K5 require derating for operation at 100 °C case temperature?

Yes. At T_C = 100 °C, continuous drain current is derated to 4 A per absolute maximum ratings. This reflects package thermal limitation-not silicon degradation-and must be applied in thermal design to maintain junction temperature ≤150 °C under worst-case ambient and airflow conditions.