STMicroelectronics STW23N85K5

Overview

STW23N85K5 from STMicroelectronics is an N-channel 850 V, 275 mΩ (max), 19 A high-voltage Power MOSFET based on MDmesh K5 vertical structure technology. It delivers ultra-low gate charge (38 nC), Zener-protected gate, and 100% avalanche tested ruggedness for high-efficiency switching in industrial HV DC-DC converters and offline SMPS.

For engineers reviewing the STW23N85K5 datasheet, STW23N85K5 pinout, STW23N85K5 application, or STW23N85K5 equivalent, key selection criteria include its 850 V V_BRDSS rating, 235 mΩ typical R_DS(on), 6 V/ns dv/dt capability, 200 mJ single-pulse avalanche energy, and TO-247 package thermal resistance of 0.5 °C/W.

Technical Context

This device implements ST's proprietary MDmesh K5 vertical superjunction architecture to minimize conduction and switching losses simultaneously. Its low FoM (R_DS(on) × Q_g = 10.4 Ω·nC) enables high power density in hard-switched topologies operating up to 100 kHz.

The integrated Zener-protected gate withstands ±30 V transient stress, while the 100% unclamped inductive switching (UIS) test ensures robustness under overcurrent fault conditions. The source-drain diode exhibits 1.5 V forward drop at 19 A and 510 ns reverse recovery time at 25 °C.

Key Specifications

Pinout & Package

Delivered in a standard TO-247 package with isolated mounting tab, optimized for high-power thermal management and PCB-level creepage/clearance compliance in >600 V systems.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IXTH20N85X and IPP65R850C7, STW23N85K5 uniquely combines 850 V rating, integrated gate Zener, and 200 mJ avalanche energy-making it the only option qualified for unclamped inductive switching in 800 V bus industrial converters without external protection.

Availability

STW23N85K5 is available at Aetrix Electronics and suitable for industrial HV DC-DC converters, offline switch-mode power supplies, and uninterruptible power supplies requiring stable component supply across multi-year production cycles.

Supply support for STW23N85K5 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, delivering silicon solutions for automotive, industrial, and power applications with emphasis on energy efficiency and system reliability.

The MDmesh K5 product line targets high-voltage power conversion systems demanding best-in-class FoM, ruggedness, and thermal performance-specifically engineered for 700–900 V industrial and telecom power architectures.

FAQ

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

The STW23N85K5 supports 12.4 A continuous drain current at T_C = 100 °C, as specified in Table 1 of DS9211 Rev 4. This derating reflects thermal limits of the TO-247 package and ensures safe operation within the SOA boundary at elevated temperatures without exceeding 150 °C junction temperature.

Does this MOSFET include integrated gate protection?

Yes - the STW23N85K5 integrates a monolithic Zener diode between gate and source, rated for ±30 V clamping. This eliminates the need for external gate protection components in most industrial layouts, reducing BOM count and improving reliability against ESD and transient overvoltage events.

Can STW23N85K5 replace IGBTs in high-voltage inverter applications?

Yes - its 850 V V_BRDSS, 19 A ID, and 200 mJ E_AS enable direct IGBT replacement in 3-level NPC and active neutral-point-clamped inverters up to 800 V DC bus. Unlike IGBTs, it offers faster switching, zero tail current, and simpler gate drive, though conduction loss may be higher at very high currents (>30 A).

What is the recommended gate resistor value for hard-switched PFC operation?

A 4.7 Ω gate resistor is validated per Figure 14 in DS9211 Rev 4 for resistive-load switching at 400 V V_DD and 9.5 A I_D. For PFC operation, 4.7–10 Ω balances switching speed (to limit EMI) and gate drive loss; values below 3.3 Ω increase risk of oscillation due to low R_g + L_stray resonance.