STMicroelectronics STF20N90K5

Overview

STF20N90K5 from STMicroelectronics is a 900 V, 20 A N-channel MDmesh™ K5 Power MOSFET in TO-220FP package, featuring 0.21 Ω typical R_DS(on), 40 nC total gate charge, and 2500 V RMS insulation withstand voltage. It delivers ultra-low conduction and switching losses for high-voltage AC-DC front-end PFC stages in industrial SMPS.

For engineers reviewing the STF20N90K5 datasheet, STF20N90K5 pinout, STF20N90K5 application, or STF20N90K5 equivalent, key selection criteria include avalanche ruggedness (500 mJ E_AS), Zener-protected gate (±30 V V_GS rating), and 4.5 V/ns diode recovery dv/dt capability under 20 A ISD stress.

Technical Context

This device employs ST's proprietary MDmesh™ K5 vertical superjunction architecture to achieve industry-leading figure of merit (R_DS(on) × Q_g = 10 nΩ·nC) and 1500 pF input capacitance at 100 V. Its optimized cell layout enables stable operation up to 150 °C junction temperature with 3.1 °C/W R_thj-case.

The integrated back-to-back gate-source Zener diodes provide ±30 V clamping without external protection, while the source-drain diode exhibits 1.5 V forward drop at 20 A and 517 ns reverse recovery time at 25 °C - critical for hard-switched totem-pole PFC designs.

Key Specifications

Pinout & Package

TO-220FP package: insulated tab, single-row 3-pin outline with internal thermal pad connected to drain. Mounting requires electrically isolated heatsink interface due to 2500 V RMS isolation rating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IXTH20N90L and IPP60R099C7, STF20N90K5 uniquely combines 900 V rating, Zener gate protection, and best-in-class FoM for space-constrained industrial PFC designs requiring zero external protection components and guaranteed avalanche survivability.

Availability

STF20N90K5 is available at Aetrix Electronics and suitable for industrial SMPS front-end, telecom rectifier modules, and EV charger auxiliary supply requiring stable component supply and long-term production continuity.

Supply support for STF20N90K5 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 industrial, automotive, and consumer markets.

STF20N90K5 belongs to the MDmesh™ K5 high-voltage Power MOSFET product line, engineered specifically for high-efficiency, high-power-density AC-DC conversion in industrial and telecom infrastructure.

FAQ

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

The STF20N90K5 supports 13 A continuous drain current at T_C = 100 °C, as specified in Table 1 of DS11634 Rev 4. This derating reflects thermal limitations of the TO-220FP package with 3.1 °C/W R_thj-case, requiring heatsink design to maintain case temperature ≤100 °C under full load.

Does this MOSFET require external gate protection components?

No - the STF20N90K5 integrates back-to-back Zener diodes between gate and source, providing ±30 V clamping per Table 8. This eliminates the need for external gate protection diodes in standard gate drive configurations, reducing BOM count and PCB area in PFC and SMPS designs.

How does its avalanche capability compare to standard 900 V MOSFETs?

With 500 mJ single-pulse E_AS at T_J = 25 °C and 6.5 A I_AR, STF20N90K5 exceeds typical 900 V MOSFETs (often 200–300 mJ) by >60%. Its 100% production avalanche testing ensures every unit meets this spec, critical for reliability in unclamped inductive switching applications like PFC chokes.

Can it be used in hard-switched totem-pole PFC topologies?

Yes - its 517 ns t_rr and 11.4 µC Q_rr at 25 °C, combined with 4.5 V/ns diode recovery dv/dt rating, enable robust operation in totem-pole PFC. However, Q_rr increases to 14 µC at 150 °C, requiring careful dead-time optimization to avoid cross-conduction losses in high-temperature environments.