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is a high-frequency Silicon N-Channel Dual-Gate MOSFET primarily used in VHF amplifier and mixer applications. Manufactured by companies like NEC, Hitachi, and Motorola
, it is a classic component often found in amateur radio equipment and older television tuners. www.jotrin.ru Key Technical Specifications
The 3SK41 is designed for low-noise, high-gain performance at high frequencies. Below are the typical parameters for this device: Drain-Source Voltage ( cap V sub cap D cap S end-sub Drain Current ( cap I sub cap D Power Dissipation ( cap P sub cap D 250mW (0.25W) Package Type: TO-72 (4-lead metal can) Drain-Source On-Resistance ( cap R sub cap D cap S open paren o n close paren end-sub Functional Overview
The dual-gate structure of the 3SK41 allows for several unique circuit advantages: Reduced Feedback Capacitance:
The second gate acts as a shield between the input gate and the drain, significantly reducing Miller effect capacitance. This provides better stability and higher gain at VHF frequencies. Automatic Gain Control (AGC):
By varying the bias on the second gate (Gate 2), the gain of the MOSFET can be controlled without significantly shifting the input impedance of Gate 1. Mixing Applications:
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:
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:
It is currently considered an obsolete or "hard-to-find" part but can still be sourced through specialty electronic distributors like Jotrin Electronics
For a detailed visual of the pinout or specific performance curves, you can find the 3SK41 PDF datasheet on sites like AllDatasheet circuit diagrams
for a specific RF amplifier or mixer design using the 3SK41? 3SK41 Datasheet, PDF - ALLDATASHEET.COM
All. Datasheet. Distributor. Manufacturer. 3SK41. 3SK4. Match, Like. No Data. 3SK40(1) 3SK45(2) Start with. No Data. No Data. End. ALLDATASHEET.COM 3SK41 - NEC/HITACHI/MOTOROLA - Jotrin Electronics
The 3SK41 is a legacy N-channel dual-gate MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) primarily designed for VHF (Very High Frequency) applications. These components were staples in the design of high-sensitivity radio equipment, particularly as amplifiers and mixers. Because this part is largely discontinued or considered "vintage," finding modern documentation requires looking back at classic semiconductor standards. 🚀 Technical Specifications Overview
The 3SK41 was engineered to provide high gain and low noise figures in high-frequency circuits. Below are the typical electrical characteristics found in the original datasheet. Drain-Source Voltage (Vds): Maximum 20V Drain Current (Id): Maximum 25mA Gate-Source Voltage (Vgs1/Vgs2): ±10V Power Dissipation (Pd): 200mW Forward Transfer Admittance (|yfs|): 10 to 18 mS Input Capacitance (Ciss): ~5.0 pF Noise Figure (NF): ~2.0 dB at 200 MHz 🛠️ Key Features and Advantages
The dual-gate structure of the 3SK41 offers specific advantages that single-gate transistors cannot match easily: 1. Superior AGC Performance
The second gate (Gate 2) is specifically designed for Automatic Gain Control (AGC). By varying the voltage on Gate 2, the gain of the amplifier can be adjusted without significantly shifting the input impedance or frequency response. 2. Low Feedback Capacitance
Dual-gate MOSFETs have very low internal feedback capacitance (Crss). This allows for high-stability amplification at VHF frequencies without the need for complex neutralization circuits. 3. Cross-Modulation Resistance
The 3SK41 is known for its linear transfer characteristics. This reduces the likelihood of "intermodulation distortion," ensuring that strong nearby signals do not drown out the weak signal you are trying to receive. 📐 Pinout and Package Information 3sk41 datasheet
The 3SK41 typically comes in a metal-can package (similar to TO-72) with four leads. Proper identification of the leads is critical for circuit stability.
Source: Usually connected to the case/shield to reduce noise. Drain: The output terminal. Gate 2: The control or AGC terminal. Gate 1: The signal input terminal. 📻 Common Applications VHF Tuners: Used in television and FM radio front-ends.
RF Amplifiers: Providing initial signal boost for weak radio waves.
Mixer Stages: Utilizing the two gates to mix the RF signal with a Local Oscillator (LO) signal efficiently.
IF Amplifiers: Standard intermediate frequency amplification in communications receivers. 🔄 Modern Alternatives and Equivalents
Since the 3SK41 is no longer in mass production, hobbyists and repair technicians often look for replacements. While no modern part is a 100% mechanical match, the following are often used in similar circuits: 3SK45: A very close relative often used interchangeably.
BF960 / BF981: Common European dual-gate MOSFETs used for VHF/UHF.
NTE161: A universal replacement part often found in repair catalogs. ⚠️ Usage Considerations
When working with a 3SK41, remember that MOSFETs are highly sensitive to Electrostatic Discharge (ESD). Even a small spark from your fingertip can puncture the thin oxide layer of the gates, destroying the transistor. Always use an anti-static wrist strap and a grounded soldering iron when handling these components.
The 3SK41 is a legacy N-channel dual-gate MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) primarily designed for high-frequency applications, such as VHF (Very High Frequency) amplifiers and mixers in radio and television tuners. Core Specifications
While specific values can vary slightly by manufacturer (historically produced by companies like Hitachi or NEC), the standard parameters for the 3SK41 include: Type: N-Channel Depletion Mode Dual-Gate MOSFET. Drain-Source Voltage ( VDScap V sub cap D cap S end-sub ): Max 20V. Drain Current ( IDcap I sub cap D ): Max 25mA. Power Dissipation ( Ptotcap P sub t o t end-sub ): Approximately 200mW to 300mW. Forward Transfer Admittance ( ): Typically 10 to 15 mS (millisiemens) at 1kHz. Input Capacitance ( Cisscap C sub i s s end-sub ): Low, typically around 5.0pF to 6.0pF.
Package: Often found in a 4-pin TO-72 metal can or similar small plastic packages. Functional Roles
The "dual-gate" design is the defining feature of the 3SK41, allowing it to excel in two specific areas:
Automatic Gain Control (AGC): By applying a control voltage to the second gate (Gate 2), you can vary the gain of the signal passing through the first gate (Gate 1). This is essential for stabilizing radio reception under varying signal strengths.
Mixing: In superheterodyne receivers, the dual-gate structure allows one gate to receive the RF (Radio Frequency) signal and the other to receive the LO (Local Oscillator) signal, mixing them with high isolation and low noise. Key Performance Features
High Power Gain: It provides significant amplification in the VHF band (up to 200–300 MHz).
Low Noise Figure: Designed to minimize the "hiss" or thermal noise added to weak signals, making it ideal for the front-end stages of receivers. AGC Operation If you vary VG2 from 2V
Low Feedback Capacitance: The dual-gate construction reduces the internal capacitance between the drain and the input gate, which improves stability and prevents unwanted oscillations at high frequencies. Typical Pinout (TO-72 Style)
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
The 3SK41 is largely considered an obsolete or "vintage" component. It is rarely used in new designs today, as it has been replaced by more modern surface-mount devices (SMD) like the BF998 or high-speed Gallium Arsenide (GaAs) FETs. However, it remains highly sought after by hobbyists for repairing vintage ham radios, scanners, and TV tuners.
While a standard essay on a datasheet might sound dry, the "3sk41" is actually a fascinating subject because it sits at the precise intersection of consumer history and electronic obsolescence. The 3SK41 is not a modern microprocessor; it is a N-channel dual-gate MOSFET, a component that was once the beating heart of the VHF and UHF tuners in analog television sets.
Here is an essay exploring the significance of this humble component.
If you vary VG2 from 2V to 6V, the forward gain (Yfs) changes by a factor of 10:1. This allows a receiver to automatically reduce gain when a strong signal is present.
The 3SK41 was developed in the late 1970s and early 1980s by Japanese manufacturers like Hitachi, NEC, and Sanyo. It was famously used in the RF front-ends of high-end analog television tuners (Channels 1-12) and FM radio receivers.
If you want, I can:
Understanding the 3SK41: A Comprehensive Guide to the 3SK41 Datasheet
The 3SK41 is a classic N-channel dual-gate MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) that has long been a staple in high-frequency applications. Primarily designed for VHF (Very High Frequency) amplifiers and mixers, it remains a point of interest for hobbyists, vintage radio restorers, and engineers working with legacy RF circuits.
If you are looking for the 3SK41 datasheet specifications, this guide breaks down the essential parameters, pinouts, and application details you need for your project. 1. Overview and Key Features
The 3SK41 is housed in a standard TO-72 metal can package. Its dual-gate construction is its defining feature, allowing for superior gain control and reduced feedback capacitance compared to single-gate FETs. Low Noise Figure: Ideal for front-end RF amplification.
High Power Gain: Provides significant signal boost in the VHF range.
Dual-Gate Design: Facilitates easy Automatic Gain Control (AGC) and mixing functions.
High Input Impedance: Minimizes loading on preceding stages. 2. Technical Specifications (Absolute Maximum Ratings)
When reviewing the 3SK41 datasheet, the absolute maximum ratings are critical to prevent component failure. Operating beyond these limits can cause permanent damage. Drain-Source Voltage Gate 1-Source Voltage Gate 2-Source Voltage Drain Current Total Power Dissipation Storage Temperature -55 to +150 3. Electrical Characteristics Under typical operating conditions (usually at ), the 3SK41 exhibits the following performance: Forward Transfer Admittance (
): Typically ranges between 10 to 20 mS (millisiemens), indicating high sensitivity. Input Capacitance ( Cisscap C i s s ): Generally around 5.0 pF. Reverse Transfer Capacitance ( Crsscap C r s s Key Historical Context The 3SK41 was developed in
): Extremely low (approx. 0.02 pF), which is vital for stability in high-frequency amplifiers. Noise Figure (NF): Typically 2.0 to 3.0 dB at 200 MHz. 4. Pinout Configuration
The 3SK41 usually follows the standard TO-72 four-lead configuration. Looking from the bottom (pins facing you), the leads are typically arranged as follows:
Source (S) / Shield (Case): Often tied together to provide grounding and shielding. Drain (D): The output lead.
Gate 2 (G2): Typically used for AGC or as the local oscillator input in mixers. Gate 1 (G1): The primary signal input lead.
(Note: Always verify the pinout with the specific manufacturer’s marking, as some variations exist.) 5. Common Applications
The 3SK41 is versatile within the RF spectrum. You will commonly find it used in:
VHF TV Tuners: Used as a low-noise RF amplifier to improve signal reception.
FM Radio Receivers: Acting as the first stage of amplification.
Mixer Circuits: Utilizing Gate 1 for the RF signal and Gate 2 for the Local Oscillator (LO) to produce an Intermediate Frequency (IF).
Signal Generators: Providing stable, high-frequency oscillations. 6. Alternatives and Equivalents
Because the 3SK41 is an older component, it can sometimes be difficult to source. If you cannot find an original, consider these common substitutes: 3SK40: Very similar characteristics, often interchangeable.
BF960 / BF961: Modern silicon N-channel dual-gate MOSFETs (though they often come in SOT packages).
3SK45: A common alternative used in similar VHF applications. Conclusion
The 3SK41 remains a respected component for RF enthusiasts due to its low noise and stable gain. Whether you are repairing a vintage transceiver or building a custom VHF pre-amplifier, understanding the 3SK41 datasheet is the first step toward a successful build. Always ensure proper ESD (Electrostatic Discharge) precautions when handling these MOSFETs, as the gates are highly sensitive to static electricity.
Based on the technical specifications found in a typical 3SK41 Datasheet (a N-channel MOSFET used in switching applications), I have developed a specific application feature.
Target Component: 3SK41 (Silicon N-Channel Power MOSFET) Key Datasheet Parameters:
| Parameter | Test Condition | Min | Typ | Max | Unit | | :--- | :--- | :--- | :--- | :--- | :--- | | Drain Current (IDSS) | VG1S = 0V | 2.5 | 7.0 | 15 | mA | | Gate 1 Cut-off Voltage | ID = 100 µA | -1.5 | -0.8 | -0.3 | V | | Forward Transfer Admittance (Yfs) | f = 100 MHz | 7 | 12 | - | mS | | Input Capacitance (Ciss) | f = 1 MHz | - | 3.5 | 5 | pF | | Reverse Transfer Capacitance (Crss) | f = 1 MHz | - | 0.05 | 0.2 | pF | | Output Capacitance (Coss) | f = 1 MHz | - | 1.8 | 2.5 | pF | | Noise Figure (NF) | f = 200 MHz, optimized | - | 4.0 | 6.0 | dB | | Power Gain (Gps) | f = 200 MHz | 18 | 23 | - | dB |