3sk41 Datasheet _top_

The 3SK41 is a high-performance N-channel dual-gate MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) primarily used in radio frequency (RF) applications. While some older records may misidentify it as a relay, it is most recognized in amateur radio and signal processing for its fast switching and low noise characteristics. Key Technical Specifications

Key specs to focus on for design and what they imply

• VDS (often low, e.g., ~20 V): device intended for low‑voltage circuits; don’t use in higher supply rails without level shifting or protection.
• VGS(max) (often ±7–10 V): gate oxide is fragile — gate surge protection and proper bias resistors are needed.
• ID and RDS(on): small currents and relatively high RDS(on) mean the part is not for power switching but for low‑power RF amplification/mixing.
• gm and ft: higher gm → higher small‑signal gain; ft indicates usable frequency range. Compare gm and ft to target RF band.
• Gate and inter‑electrode capacitances (Cgs, Cgd, Cds): set the device’s loading on preceding stages and influence matching network values; large Crss can cause feedback and instability at high frequencies.
• Dual gates: the second gate provides control (gain/VFO mixing) or shielding — datasheet shows transfer ratios for Gate1 and Gate2 and coupling between them.

• BF998 (NXP/Infineon): SOT-143 package. Superior noise figure (1.5dB at 200MHz). Pinout similar but requires careful biasing.
• 3SK299 (Renesas): The spiritual successor. Lower noise, higher gain.
• MOSFET Dual-Gate: MFE201, MFE121.

Primary Application: RF amplifiers, balanced mixers, and signal converters in communication equipment. Key Features: 3sk41 datasheet

The 3SK41 represents a pivotal chapter in the history of consumer electronics: The Golden Age of RF: The 3SK41 is a high-performance N-channel dual-gate MOSFET

It is currently considered an obsolete or "hard-to-find" part but can still be sourced through specialty electronic distributors like Jotrin Electronics VDS (often low, e

The following specifications are common for the 3SK41 dual-gate MOSFET: Type: N-channel dual-gate MOS field-effect transistor. Package: Typically found in a CAN-4 (metal can) package.

When looking at the bottom of a TO-72 metal package (with the tab as a reference): Source (often connected to the case) Drain Gate 2 Gate 1 Modern Availability