STMicroelectronics STN1N20

Overview

STN1N20 from STMicroelectronics is an N-channel 200 V, 1.2 Ω (max 1.5 Ω), 1 A SOT-223 Power MOSFET using MESH OVERLAY™ process technology, designed for switching in lighting converters and low-power DC-DC applications where avalanche ruggedness and compact footprint are critical.

For engineers reviewing the STN1N20 datasheet, STN1N20 pinout, STN1N20 application, or STN1N20 equivalent, key selection criteria include its 200 V V_DSS, 1.2 Ω R_DS(on) at V_GS = 10 V, 100% avalanche-tested reliability, SOT-223 thermal performance (R_thj-pcb = 43 °C/W), and gate charge profile (Q_g = 11–15.7 nC).

Technical Context

This device employs ST's proprietary high-voltage MESH OVERLAY™ process with STrip layout and edge termination, enabling robust unclamped inductive switching and stable operation up to 150 °C junction temperature. Its 100% avalanche-tested rating (E_AS = 10 mJ, I_AR = 1 A) supports reliable operation in flyback and buck-derived lighting drivers.

The SOT-223 package provides enhanced PCB heat spreading versus SOT-23, with verified R_thj-pcb = 43 °C/W and R_thj-amb = 60 °C/W. Gate threshold voltage (V_GS(th) = 2–4 V) ensures compatibility with standard 3.3 V/5 V logic-level drive while maintaining noise immunity.

Key Specifications

Pinout & Package

SOT-223 package with exposed drain pad (Pin 2) for thermal conduction and mechanical anchoring; standardized 4-pin configuration with source (Pin 1), gate (Pin 3), and drain (Pin 2 & Pin 4 electrically tied).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar N-channel 200 V, 1 A Power MOSFET applications.

Compared with STP1NK20Z and IRF630B, STN1N20 uniquely balances SOT-223 form factor, 10 mJ avalanche rating, and 1.2 Ω R_DS(on), making it optimal for thermally constrained, high-reliability lighting and industrial switching where TO-92 lacks power handling and TO-220 adds size/cost.

Availability

STN1N20 is available at Aetrix Electronics and suitable for LED driver secondary side switches, flyback converter primary switches, DC-DC buck regulators, and industrial sensor power switches requiring stable component supply and long-term lifecycle support.

Supply support for STN1N20 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 for automotive, industrial, and consumer markets.

The STN1N20 belongs to ST's MESH OVERLAY™ Power MOSFET product line, engineered specifically for high-voltage, low-power switching applications such as LED lighting drivers and compact offline power supplies where avalanche robustness and thermal efficiency are essential.

FAQ

Is STN1N20 suitable for 230 V AC input LED drivers?

Yes. With 200 V V_DSS, STN1N20 supports peak rectified voltages up to ~325 V when used with appropriate derating and clamping. Its 100% avalanche testing (E_AS = 10 mJ) ensures reliability against transformer leakage spikes common in flyback-based 230 V AC LED drivers.

What is the maximum continuous drain current at 85 °C case temperature?

At T_C = 85 °C, the maximum continuous drain current is approximately 0.74 A, calculated by linear derating from 1 A at 25 °C using the 0.023 W/°C derating factor and R_DS(on) = 1.5 Ω, resulting in 0.74 A × 1.5 Ω = 0.83 W ≤ (2.9 W − (85−25) × 0.023 W).

Can STN1N20 replace a bipolar transistor in a low-frequency switching application?

Yes. As an N-channel enhancement-mode MOSFET, STN1N20 offers lower drive power, faster switching, and no base current requirement versus a BJT. Its 2–4 V V_GS(th) allows direct 3.3 V/5 V logic drive, and 1.2 Ω R_DS(on) yields lower saturation loss than typical BJT V_CE(sat) at 1 A.

Does STN1N20 have built-in ESD protection on the gate?

No. The datasheet does not specify integrated gate ESD protection. External 10 kΩ gate resistor and 10–100 nF gate-to-source capacitor are recommended for noise suppression and transient protection in industrial environments per standard MOSFET layout practices.