3sk41 Datasheet ✦ Exclusive

This article serves as an exhaustive resource. We will explore the official specifications, pinout, equivalent parts, application circuits, and the critical differences between the original 3SK41 and modern variants like the 3SK41A and 3SK41B.

The original highlights it as an ideal choice for electronic tuners in TVs and VCRs, as well as FM radio front-ends.

These electrical characteristics are critical for understanding the 3SK41's performance. The high of 200 Ω is a key characteristic of this MOSFET. The output capacitance (Coss) of 5 pF is small, allowing for the fast switching speeds necessary for VHF applications. 3sk41 datasheet

Ciss(max)cap C sub i s s open paren m a x close paren end-sub Maximum capacitance seen looking into the gate Anatomy of a Dual-Gate MOSFET

Used in receiver RF amplifiers and balanced mixer stages, particularly in legacy radio gear. Equivalents: If the 3SK41 is unavailable, common substitutes include the 3SK40, 2SK701, 2SK702, and 2SK703 Legacy Availability: This article serves as an exhaustive resource

The 3SK41 features a classic four-lead . Looking at the bottom of the transistor (leads facing you, with the orientation tab pointing downward/clockwise), the pinout assignment follows the industry standard for dual-gate RF FETs:

In mixer circuits, the local oscillator signal can be applied to Gate 2 while the RF signal is applied to Gate 1, allowing for efficient frequency conversion with low cross-modulation. Applications & Substitutes Common Uses: Ciss(max)cap C sub i s s open paren

Because the 3SK41 is an obsolete part, sourcing original components may require specialized vintage component distributors like Littlediode . If direct replacements are unavailable, several drop-in or near-equivalent dual-gate N-channel MOSFETs can be used to repair or substitute the circuit:

While implementing this feature, the designer must adhere to the graph in the 3SK41 datasheet. During the soft-start ramp, the transistor passes through the linear region where both Voltage ($V_DS$) and Current ($I_D$) are high. The soft-start duration must be calculated carefully so that the transient thermal limit of the 3SK41 is not exceeded during this transition.