STMicroelectronics STF11N52K3

Overview

STF11N52K3 from STMicroelectronics is an N-channel SuperMESH3™ Power MOSFET in TO-220FP package, rated for 525 V drain-source voltage, 0.41 Ω typical R_DS(on) at V_GS = 10 V and 5 A, 10 A continuous drain current at T_C = 25 °C, and 30 W total power dissipation. It delivers high avalanche ruggedness (170 mJ E_AS) and fast switching (t_r = 18 ns, t_f = 42 ns) for offline SMPS and AC-DC adapters.

For engineers reviewing the STF11N52K3 datasheet, STF11N52K3 pinout, STF11N52K3 application, or STF11N52K3 equivalent, key selection criteria include its 525 V blocking capability, Zener-protected gate, low C_oss (110 pF), improved diode reverse recovery (t_rr = 270 ns), and TO-220FP thermal resistance of 4.17 °C/W - critical for compact, convection-cooled power stages.

Technical Context

This MOSFET employs ST's SuperMESH3™ vertical structure to achieve ultra-low on-resistance while maintaining high dv/dt immunity (12 V/ns) and robust unclamped inductive switching performance. Its integrated back-to-back gate-source Zener diodes (BVGSO = 30 V) eliminate external protection components and ensure reliable gate drive integrity under transient conditions.

The device features optimized dynamic parameters: Q_g = 51 nC, Q_gd/Q_gs ratio of ~4:1, and C_iss/C_oss = 1400/110 pF - enabling efficient hard-switching operation up to several hundred kHz in flyback and resonant converters.

Key Specifications

Pinout & Package

STF11N52K3 uses the TO-220FP (Full-Pak) package: insulated plastic case with internal heatsink tab, 3-pin single-ended configuration, and 4.17 °C/W junction-to-case thermal resistance. The package is lead-free, RoHS-compliant, and ECOPACK® certified.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage N-channel MOSFET applications.

Compared with STP11N52K3 and STB11N52K3, the STF11N52K3 uniquely balances moderate power handling (30 W), insulation (TO-220FP base isolation), and compact through-hole mounting - making it optimal for mid-power, cost-sensitive, convection-cooled AC-DC designs.

Availability

STF11N52K3 is available at Aetrix Electronics and suitable for AC-DC adapters, flyback SMPS, and industrial lighting ballasts requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for STF11N52K3 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, discrete devices, and MEMS sensors for automotive, industrial, and consumer markets.

The SuperMESH3™ Power MOSFET product line targets high-efficiency, high-reliability offline power conversion - specifically engineered to replace older planar MOSFETs in 50–300 W SMPS, PFC, and lighting applications with superior R_DS(on)-to-voltage trade-offs.

FAQ

What is the maximum gate-source voltage rating for STF11N52K3?

The absolute maximum V_GS is ±30 V, enforced by integrated back-to-back Zener diodes with 30 V breakdown (BVGSO). This eliminates external gate protection components and allows direct connection to standard 12–15 V gate drivers without risk of oxide damage.

Does STF11N52K3 require a heatsink in typical 25 W adapter applications?

Yes - although rated for 30 W at T_C = 25 °C, its TO-220FP R_thj-case is 4.17 °C/W. At 25 W dissipation, junction temperature would exceed 150 °C without heatsinking. A small extruded or stamped heatsink (≤15 cm²) is required to maintain T_J < 125 °C at full load.

How does the source-drain diode recovery compare to standard MOSFETs?

At I_SD = 10 A and di/dt = 100 A/µs, t_rr = 270 ns and Q_rr = 2700 nC - significantly improved over legacy 500 V MOSFETs (typically >500 ns, >4000 nC). This reduces switching losses and EMI in discontinuous-mode topologies and enables faster dead-time optimization.

Can STF11N52K3 be used in place of STP11N52K3 in existing TO-220 PCB footprints?

No - STF11N52K3 uses TO-220FP (Full-Pak), which has an insulated tab and different pin spacing versus TO-220. The mounting hole and tab clearance differ, and thermal interface requirements change due to the plastic insulation layer. Mechanical redesign is required for substitution.