STMicroelectronics STP5N120

Overview

STP5N120 from STMicroelectronics is an N-channel 1200 V, 2.7 Ω (typ), 4.7 A SuperMESH™ Power MOSFET in TO-220 package with integrated gate-source Zener protection (30 V), 4000 V HBM ESD rating, and 400 mJ single-pulse avalanche energy. It serves as a high-voltage switching device in offline SMPS, PFC stages, and industrial AC-DC converters where robust dv/dt immunity (>4 V/ns) and avalanche ruggedness are required.

For engineers reviewing the STP5N120 datasheet, STP5N120 pinout, STP5N120 application, or STP5N120 equivalent, key selection criteria include verified 1200 V blocking capability, R_DS(on) ≤ 3.5 Ω at 10 V_GS, thermal resistance of 0.78 °C/W (j-case), built-in Zener-protected gate, and SOA-limited pulsed current of 18.8 A.

Technical Context

This MOSFET employs ST's strip-based SuperMESH™ layout to minimize R_DS(on) while preserving high-voltage integrity and dv/dt hardness. Its internal gate-source Zener diode (BVGSO = 30 V) clamps transients without external components, directly enabling reliable operation in noisy high-side switch configurations.

The device features fully characterized avalanche performance (IAS = 4.7 A, EAS = 400 mJ), low Crss (19 pF) for reduced Miller effect, and optimized gate charge (Qg = 57 nC, Qgd = 31 nC) to support efficient 600 V hard-switching at moderate frequencies. Safe operating area is defined up to 160 W at T_C = 25 °C with 1.28 W/°C derating.

Key Specifications

Pinout & Package

TO-220 package (Type A), 3-terminal through-hole housing with isolated tab (drain-connected). Mounting hole ∅P = 3.75–3.85 mm; lead pitch e1 = 4.95–5.15 mm; case height L = 13–14 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STW5N120 and FQP5N120, STP5N120 offers optimal balance of TO-220 manufacturability, integrated Zener safety, and proven 400 mJ avalanche margin-making it preferred for cost-sensitive, medium-power industrial SMPS where gate protection and thermal simplicity are critical.

Availability

STP5N120 is available at Aetrix Electronics and suitable for industrial SMPS, AC-DC adapters, and high-voltage lighting ballasts requiring stable component supply and long-term obsolescence management.

Supply support for STP5N120 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 SuperMESH™ Power MOSFET product line targets high-efficiency, high-reliability switching in 600–1700 V applications-specifically engineered for offline power conversion, PFC, and motor control where avalanche ruggedness and dv/dt immunity are non-negotiable.

FAQ

Is STP5N120 still in active production?

No-STP5N120 is marked "Obsolete Product(s)" in its official datasheet (Doc ID 13530 Rev 2, Nov 2009). STMicroelectronics discontinued this part; however, Aetrix Electronics maintains legacy inventory with full traceability and provides last-time-buy support, including extended warranty and cross-reference assistance for migration paths.

Can STP5N120 replace STP6N120 in existing designs?

STP6N120 has higher current rating (6 A vs 4.7 A) and lower R_DS(on) (2.2 Ω typ), but shares identical 1200 V rating, TO-220 package, and SuperMESH™ architecture. Direct replacement is electrically feasible only if peak/continuous current remains ≤4.7 A and thermal design accommodates +15% conduction loss; verify SOA curves under actual operating conditions.

What is the maximum safe gate resistor value for STP5N120?

Based on Qg = 57 nC and typical ±1 A gate driver output, RG ≤ 4.7 Ω ensures <60 ns turn-on delay and keeps switching losses within datasheet-defined SOA limits. Higher values (e.g., 10–22 Ω) increase switching time and risk thermal runaway during hard switching at 600 V; use 4.7 Ω as default unless gate drive strength is confirmed ≥±1.5 A.

Does the built-in Zener protect against negative VGS transients?

Yes-the gate-source Zener (BVGSO = 30 V) is bidirectional: it clamps both positive and negative transients exceeding ±30 V. This protects against negative spikes induced by transformer leakage or parasitic coupling during turn-off, eliminating need for external bipolar TVS diodes in most industrial layouts.