STMicroelectronics STW43NM50N

Overview

STW43NM50N from STMicroelectronics is an N-channel 500 V, 37 A, 0.070 Ω R_DS(on) MDmesh™ II Power MOSFET in TO-247 package, designed for high-efficiency switching converters. It features 100% avalanche testing, low gate charge (140 nC), and low input capacitance (4200 pF), enabling fast switching in SMPS, PFC, and industrial motor drives.

For engineers reviewing the STW43NM50N datasheet, STW43NM50N pinout, STW43NM50N application, or STW43NM50N equivalent, key selection criteria include its 500 V V_DSS, 37 A continuous drain current at 25 °C, 0.49 °C/W R_thj-case, 15 V/ns dv/dt capability, and 1000 mJ single-pulse avalanche energy - all critical for hard-switched high-voltage topologies.

Technical Context

This device implements ST's second-generation MDmesh™ vertical structure with strip layout, delivering ultra-low on-resistance and gate charge simultaneously. Its 500 V breakdown voltage (V_(BR)DSS) is guaranteed at 1 mA, and it sustains 15 V/ns dv/dt under inductive turn-off conditions with ID = 37 A.

The integrated body diode exhibits 530 ns reverse recovery time (trr) and 11 µC Q_rr at 25 °C, optimized for snubberless operation in resonant and quasi-resonant converters. Thermal resistance junction-to-case is fixed at 0.49 °C/W, supporting high-power density mounting on heatsinks.

Key Specifications

Pinout & Package

TO-247 package: isolated tab (drain), 3-pin through-hole configuration with standard lead spacing and 14.5 mm minimum creepage distance. Mounting hole Ø3.6 mm centered on tab.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IPP60R099C7 and STW34NB20, STW43NM50N uniquely balances 500 V rating, 37 A current, and 0.070 Ω on-resistance in TO-247 - making it optimal for 380–400 V DC bus converters where both voltage headroom and conduction efficiency are critical.

Availability

STW43NM50N is available at Aetrix Electronics and suitable for server PSUs, industrial PFC modules, solar DC-DC converters, and EV onboard charger designs requiring stable component supply and long-term production continuity.

Supply support for STW43NM50N 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 and discrete power devices for industrial, automotive, and consumer markets.

This device belongs to ST's MDmesh™ II Power MOSFET product line, engineered specifically for high-efficiency, high-frequency switching power supplies operating above 50 kHz with demanding thermal and ruggedness requirements.

FAQ

Is STW43NM50N still in active production?

No - STW43NM50N is marked as Obsolete Product(s) in ST's official documentation (Doc ID 14168 Rev 5, Jan 2010). It remains available through authorized distributors and Aetrix Electronics' legacy inventory with full traceability, but no new wafer fabrication is scheduled. Customers should evaluate ST's MDmesh™ DM6 or H series as functional upgrades.

What is the maximum safe operating area (SOA) limitation at 100 °C case temperature?

At T_C = 100 °C, the continuous drain current is derated to 23 A per Absolute Maximum Ratings Table 2. The SOA curve (Figure 2) shows that pulsed operation at 148 A is limited to ≤100 µs pulse width to avoid secondary breakdown, with V_DS constrained to ≤250 V at that current level.

Can STW43NM50N be used in synchronous rectification configurations?

No - STW43NM50N is a standard N-channel enhancement-mode MOSFET with non-optimized body diode characteristics (trr = 530 ns, Q_rr = 11 µC). It lacks the low-Q_rr, soft-recovery body diode required for synchronous rectifier operation. Dedicated SR controllers paired with logic-level FETs are recommended instead.

What is the recommended gate resistor value for 100 kHz hard-switched operation?

A 4.7 Ω gate resistor is validated in the datasheet (Table 7) for 250 V/18.5 A switching with td(off) = 140 ns and tf = 42 ns. For 100 kHz operation with reduced EMI, a 10 Ω resistor is recommended to limit di/dt and suppress ringing, accepting a ~15% increase in switching loss based on Q_g = 140 nC and V_GS swing of 12 V.