STMicroelectronics STF19NM50N

Overview

STF19NM50N from STMicroelectronics is an N-channel 500 V, 14 A Power MOSFET using MDmesh II technology in a TO-220FP package, with R_DS(on) = 200 mΩ (typ), Q_g = 34 nC, and 100% avalanche tested. It serves as a high-voltage switching device in offline SMPS, PFC stages, and industrial motor drives requiring low conduction and switching losses.

For engineers reviewing the STF19NM50N datasheet, STF19NM50N pinout, STF19NM50N application, or STF19NM50N equivalent, key selection criteria include its 500 V V_DS, 200 mΩ typ R_DS(on), 34 nC total gate charge, 100% unclamped inductive avalanche rating (E_AS = 208 mJ), and TO-220FP thermal resistance (R_thJC = 1.14 °C/W).

Technical Context

This MOSFET employs ST's second-generation MDmesh vertical strip architecture to minimize both on-resistance and gate charge simultaneously-enabling high-efficiency operation at 50–100 kHz in hard-switched converters. Its low C_iss (1000 pF) and C_rss (3 pF) support fast, low-loss switching with reduced Miller effect.

The integrated body diode features t_rr = 296 ns (T_J = 25 °C) and Q_rr = 3.5 µC, optimized for snubberless flyback and resonant topologies. The device is rated for continuous operation up to T_J = 150 °C and withstands 2.5 kV RMS insulation voltage between leads and heatsink.

Key Specifications

Pinout & Package

STF19NM50N uses the TO-220FP (Full-Pak) package: insulated plastic case with metal tab acting as drain (D), enabling direct heatsink mounting without insulator. Pin 1 = Gate (G), Pin 2 = Drain (D/TAB), Pin 3 = Source (S).

Key Features

Applications

Equivalent & Alternatives

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

Compared with STP19NM50N and STW19NM50N, the STF19NM50N uniquely combines TO-220FP insulation, lowest thermal resistance among the three, and identical electrical performance-making it optimal for cost-sensitive, high-volume power supplies requiring simplified thermal management.

Availability

STF19NM50N is available at Aetrix Electronics and suitable for industrial motor drives, telecom rectifier modules, server PSUs, and EV charger PFC stages requiring stable component supply and qualified production lots.

Supply support for STF19NM50N 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 automotive, industrial, and consumer markets.

The STF19NM50N belongs to ST's MDmesh II Power MOSFET product line, engineered specifically for high-efficiency, high-voltage switching in offline SMPS, PFC, and industrial power conversion-prioritizing low R_DS(on) × Q_g and avalanche ruggedness.

FAQ

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

The STF19NM50N supports 10 A continuous drain current at T_C = 100 °C, as specified in Table 1 of DS6706. This derating reflects thermal limits of the TO-220FP package and ensures safe operation within the SOA boundary at elevated temperatures without exceeding T_J = 150 °C.

Does the STF19NM50N require a gate resistor for stability?

Yes-a gate resistor (typically 4.7 Ω) is recommended to dampen ringing caused by PCB trace inductance interacting with the device's 4.4 Ω intrinsic gate resistance and 34 nC Q_g. Data sheet Figure 15 confirms this value yields optimal t_d(on), t_r, t_d(off), and t_f with minimal overshoot in resistive-load tests.

Can the STF19NM50N replace older 500 V MOSFETs like STP16NF50 in existing designs?

Direct replacement is feasible only if layout accommodates TO-220FP's insulated tab and gate drive can source 34 nC. While R_DS(on) is 30% lower than STP16NF50's 360 mΩ, the higher Q_g demands stronger gate drivers; layout review for parasitic inductance and thermal path is essential before drop-in use.

Is the body diode suitable for synchronous rectification?

No-the body diode has t_rr = 296 ns and Q_rr = 3.5 µC, making it unsuitable for synchronous rectification above ~50 kHz. It is optimized for clamping and freewheeling in hard-switched topologies, not low-loss bidirectional conduction; external Schottky or MOSFET synchronous rectifiers are required for high-frequency SR.