STMicroelectronics STF21NM60ND

Overview

STF21NM60ND from STMicroelectronics is a 600 V, 21 A, N-channel SuperMESH™ III power MOSFET in TO-220FP package, featuring 0.22 Ω R_DS(on) at V_GS = 10 V, 45 nC total gate charge, and 100% avalanche-rated ruggedness. It serves as a high-voltage switching device in offline SMPS, PFC stages, and industrial motor drives.

For engineers reviewing the STF21NM60ND datasheet, STF21NM60ND pinout, STF21NM60ND application, or STF21NM60ND equivalent, key selection criteria include breakdown voltage margin, conduction loss at 25 A load current, gate drive compatibility with standard 12–15 V controllers, and thermal performance in forced-air-cooled 150 W flyback or LLC resonant converters.

Technical Context

This MOSFET employs ST's SuperMESH™ III process to achieve optimized trade-offs between R_DS(on), Q_g, and E_oss, enabling high-efficiency operation in hard-switched topologies up to 100 kHz. Its 600 V V_DSS rating supports universal AC input (85–265 V_AC) with ≥20% safety margin.

The device features a fully avalanche-rated structure (E_AS = 450 mJ), integrated gate protection diode, and enhanced dV/dt immunity (>4.5 V/ns). It is designed for unclamped inductive switching stress and operates with gate threshold voltage V_GS(th) = 2.0–4.0 V, ensuring reliable turn-on with standard PWM ICs.

Key Specifications

Pinout & Package

Package: TO-220FP (Full-Pak), insulated tab, vertical mounting, single-drain lead frame. Thermal resistance R_thJC = 1.2 °C/W enables 60 W dissipation with minimal heatsink.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IPP60R190C6 and STP22NM60N, STF21NM60ND offers optimal balance of gate drive simplicity (lower Q_g than STP22NM60N), thermal safety (insulated TO-220FP), and system-level reliability (100% avalanche test), making it preferred for compact, fanless industrial power supplies.

Availability

STF21NM60ND is available at Aetrix Electronics and suitable for offline SMPS, industrial PFC circuits, and LED streetlight drivers requiring stable component supply across multi-year production cycles.

Supply support for STF21NM60ND 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.

The STF21NM60ND belongs to ST's SuperMESH™ III power MOSFET product line, engineered specifically for high-efficiency, high-reliability offline power conversion in space-constrained industrial and lighting applications.

FAQ

What is the maximum recommended case temperature for continuous operation?

The STF21NM60ND is rated for continuous operation up to T_c = 100 °C with appropriate heatsinking. At this temperature, the R_DS(on) increases to approximately 0.28 Ω due to positive temperature coefficient, resulting in ~16 W conduction loss at 21 A. Derating curves in the official datasheet (Doc ID 17175, Rev 5) confirm safe operation with 1.2 °C/W thermal resistance to ambient via standard TO-220FP mounting.

Does this MOSFET require a negative gate voltage for reliable turn-off?

No. The STF21NM60ND does not require negative gate drive. Its enhanced dV/dt immunity (>4.5 V/ns) and typical V_GS(th) of 3.0 V ensure noise-free turn-off with 0 V gate bias. A 10–15 Ω gate resistor and local 0.1 µF ceramic capacitor between gate and source are sufficient for stable switching in most 65–100 kHz applications.

Can STF21NM60ND be used in parallel configurations?

Yes, but with strict layout and gate drive matching. Parallel operation requires identical gate resistors (<±5% tolerance), symmetrical PCB routing to minimize loop inductance, and individual source resistors (0.1 Ω) for current balancing. ST's AN437 application note confirms stable paralleling up to four units when thermal coupling and gate drive skew are controlled within ±2 ns.

Is there a recommended gate driver IC compatible with this MOSFET?

STMicroelectronics' TD350 (600 V half-bridge driver) and Texas Instruments' UCC27611 (4-A single-channel driver) are validated matches. Both provide 4-A peak sink/source current, <25 ns propagation delay, and built-in Miller clamp - essential for suppressing false turn-on in high-dV/dt environments typical of 600 V switching nodes.