3sk41 Datasheet May 2026

Interpreting the 3SK41 datasheet — practical guide for engineers and hobbyists

Summary: the 3SK41 is an N‑channel dual‑gate MOSFET (small RF/low‑power device in a CAN/TO‑style metal can) used historically in VHF/UHF tuner and RF front‑end circuits. Below I break down what a datasheet for this part usually contains, explain the key specs, show how they affect circuit behavior, give practical tips for selection, testing, PCB layout and replacement/cross‑reference, and include simple application examples.

Practical selection tips

Match the device to the frequency band: choose a part whose ft and gain graphs cover your intended band; dual‑gate MOSFETs are ideal for VHF/UHF tuners and mixers.
Use conservative margins on voltage/current/power ratings: design at ≤50–70% of absolute ratings for reliability in real environments.
Consider noise and linearity: if building low‑noise RF amplifiers, check noise figure and intermodulation specs (if available). If unavailable, bench‑measure.
Package matters: metal can (CAN‑4/TO) has good thermal and shielding properties for RF; choose package supporting your assembly process.

Part 8: Where to Find the Original 3SK41 Datasheet PDF

While this article consolidates the critical information, some users need the original scanned document. 3sk41 datasheet

Datasheet Archive (datasheetarchive.com): The most reliable source for obsolete Japanese datasheets. Search "Hitachi 3SK41".
Alldatasheet (alldatasheet.com): Has multiple versions, but be wary of low-resolution scans.
Electronica (electroschematics.com): User-uploaded repositories often hold the NEC or Sanyo variant.
Technical Library (bitsavers.org): Search for "Semiconductor Data Library Volume 4" from Hitachi.

If you fail to find the PDF, use the specifications listed in Part 2 of this article—they are verified against three independent component databases. Interpreting the 3SK41 datasheet — practical guide for

Cross‑reference and replacements

Older parts like 3SK41 may be manufactured by NEC, Hitachi, Motorola; look for exact electrical characteristics (VDS, gm, Cgd) rather than only part number.
When substituting, ensure package pinout, thermal dissipation and capacitance/gain profiles match closely; dual‑gate operation behavior must be similar.
If no drop‑in replacement exists, redesign the matching network and bias for the new device using the datasheet graphs.