STMicroelectronics STW8N90K5

Overview

STW8N90K5 from STMicroelectronics is a high-voltage N-channel Power MOSFET using MDmesh K5 technology, rated for 900 V V_DS, 680 mΩ R_DS(on) max at 10 V V_GS, and 8 A continuous drain current at T_C = 25 °C. It features ultra-low gate charge (11 nC), 100% avalanche tested capability (250 mJ E_AS), and Zener-protected gate, targeting high-efficiency switch-mode power supplies and industrial HV DC-DC converters.

For engineers reviewing the STW8N90K5 datasheet, STW8N90K5 pinout, STW8N90K5 application, or STW8N90K5 equivalent, key selection criteria include its 900 V breakdown voltage, 750 pF C_iss (typ.), 0.96 °C/W R_thJC, 4.5 V/ns diode recovery dv/dt rating, and TO-247 package thermal performance in hard-switched PFC and resonant LLC stages.

Technical Context

This device implements ST's proprietary vertical MDmesh K5 structure to minimize conduction and switching losses simultaneously. Its 600 mΩ typical R_DS(on) at 10 V V_GS and 11 nC total gate charge enable high-frequency operation up to 100 kHz in telecom rectifiers and solar string inverters.

The integrated Zener-protected gate withstands ±30 V V_GS, while its 100% unclamped inductive switching (UIS) test ensures ruggedness under transient overloads. The source-drain diode exhibits 371 ns t_rr and 4.27 µC Q_rr at 25 °C, supporting moderate-speed synchronous rectification in flyback topologies.

Key Specifications

Pinout & Package

STW8N90K5 uses a TO-247 package with isolated tab (drain-connected), optimized for high-voltage isolation and thermal transfer via screw-mount heatsinking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STW12N95K5 and IXTH8N90L2, STW8N90K5 offers optimal balance of 900 V rating, 680 mΩ on-resistance, and 11 nC gate charge-making it ideal for space-constrained, high-efficiency 800 V systems where thermal management and driver simplicity are prioritized over raw current headroom or lowest BOM cost.

Availability

STW8N90K5 is available at Aetrix Electronics and suitable for industrial motor drives, telecom rectifiers, solar string inverters, and UPS systems requiring stable component supply across multi-year production cycles.

Supply support for STW8N90K5 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.

STW8N90K5 belongs to the MDmesh K5 high-voltage Power MOSFET product line, engineered specifically for high-efficiency, high-power-density switch-mode power conversion in 600–1000 V applications.

FAQ

What is the maximum safe operating temperature for STW8N90K5?

The STW8N90K5 has an operating junction temperature range up to 150 °C, with thermal resistance R_thJC of 0.96 °C/W. When mounted on a properly sized heatsink with ≤10 °C/W R_thHA, it safely dissipates 130 W at T_C = 25 °C. Derating is required above 25 °C case temperature per the SOA curve in Figure 1 of DS11943.

Does STW8N90K5 require a gate resistor, and what value is recommended?

Yes-a gate resistor is required to dampen ringing and control dV/dt. For 100 kHz switching with a 1 A peak gate driver, a 4.7 Ω resistor is recommended (per Table 6 test conditions). Lower values (2.2–3.3 Ω) may be used for faster turn-on if layout parasitics are minimized and EMI constraints allow.

Can STW8N90K5 replace older STW8N90K3 or STW8N90K4 devices?

Yes-STW8N90K5 is a direct drop-in replacement for STW8N90K3/K4 in the same TO-247 package, offering improved R_DS(on) (680 mΩ vs 750 mΩ), lower Q_g (11 nC vs 13 nC), and enhanced avalanche ruggedness (250 mJ vs 200 mJ). No PCB or driver changes are needed for most designs.

Is the body diode suitable for synchronous rectification in flyback converters?

The integrated body diode has 371 ns reverse recovery time and 4.27 µC Q_rr at 25 °C, making it usable in low-frequency (<65 kHz) flyback converters with careful snubber design. However, for high-efficiency or high-frequency operation, an external Schottky or GaN FET is preferred due to its relatively high Q_rr and 1.5 V forward drop.