2N5486 N-Channel JFET Technical Summary

Overview

The 2N5486 is a symmetrical N-channel junction field-effect transistor (JFET) designed for low-noise amplification applications. This silicon-based component features interchangeable drain and source terminals, making it highly versatile in circuit design. With its excellent noise performance and stable characteristics, the 2N5486 is particularly suitable for audio and RF applications where signal integrity is paramount.

This device operates in depletion mode, requiring negative gate-to-source voltage for proper operation in most configurations. The symmetrical design allows for greater flexibility in circuit layout while maintaining consistent performance characteristics.

Features

• Low noise figure for high-quality signal amplification
• Symmetrical design with interchangeable drain and source terminals
• High input impedance for minimal loading of preceding stages
• Excellent linearity for distortion-free amplification
• Stable performance across temperature variations
• Low leakage current for improved efficiency
• Wide dynamic range suitable for various signal levels

Applications

The 2N5486 finds use in numerous electronic applications where its combination of low noise and high input impedance are particularly valuable:

Audio Applications

• Preamplifiers for musical instruments
• Phono cartridge amplifiers
• Microphone preamps
• High-fidelity audio equipment
• Equalizer circuits

RF and Communication Systems

• RF amplifier stages
• Oscillator circuits
• Mixer applications
• Impedance matching circuits
• Receiver front-end circuits

Test and Measurement

• Low-noise probe amplifiers
• Sensitive measurement equipment
• Signal conditioning circuits
• Impedance buffers

Electrical Characteristics

The following specifications are typical at 25°C unless otherwise noted:

Absolute Maximum Ratings

• Gate-Source Voltage (V_GS): ±40V
• Drain-Gate Voltage (V_DG): ±40V
• Drain Current (I_D): 25mA
• Total Device Dissipation (P_D): 350mW at 25°C
• Operating Junction Temperature Range: -55°C to +150°C
• Storage Temperature Range: -55°C to +150°C

Electrical Characteristics

• Gate-Source Cutoff Voltage (V_GS(off)): -0.3V to -3.5V
• Zero-Gate-Voltage Drain Current (I_DSS): 4mA to 20mA
• Forward Transconductance (g_fs): 3000µS to 8000µS
• Gate-Source Leakage Current (I_GSS): -1nA maximum at V_GS = -20V
• Input Capacitance (C_iss): 4pF typical at V_GS = 0V, f = 1MHz
• Output Capacitance (C_oss): 2pF typical at V_GS = 0V, f = 1MHz
• Reverse Transfer Capacitance (C_rss): 1pF typical at V_GS = 0V, f = 1MHz
• Noise Figure (NF): 2dB typical at f = 1kHz, I_D = 1mA

Package Information

The 2N5486 is available in several package options to accommodate different application requirements:

TO-92 Package

• Package Type: Molded plastic, through-hole
• Dimensions: 4.7mm x 3.7mm x 4.9mm (typical)
• Lead Spacing: 2.54mm (0.1 inch) standard
• Pin Configuration:
  • Pin 1: Drain
  • Pin 2: Gate
  • Pin 3: Source
• Weight: Approximately 0.15 grams
• Moisture Sensitivity Level (MSL): MSL 1 - Unlimited

SOT-23 Surface Mount Package

• Package Type: Small Outline Transistor
• Dimensions: 2.9mm x 1.3mm x 0.95mm
• Lead Pitch: 0.95mm
• Pin Configuration:
  • Pin 1: Gate
  • Pin 2: Source
  • Pin 3: Drain
• Weight: Approximately 0.008 grams
• Moisture Sensitivity Level (MSL): MSL 1 - Unlimited

Performance Characteristics

The 2N5486 exhibits several notable performance characteristics that make it suitable for demanding applications:

Transfer Characteristics

The device shows a square-law transfer characteristic typical of JFETs, with good linearity in the operating region. The pinch-off voltage (V_GS(off)) typically ranges between -0.3V and -3.5V, allowing for flexible biasing arrangements.

Noise Performance

With a typical noise figure of 2dB at 1kHz, the 2N5486 excels in low-noise applications. The noise performance remains excellent across the audio frequency range, making it particularly suitable for high-quality audio amplification.

Frequency Response

The combination of low capacitances and high transconductance gives the 2N5486 good high-frequency performance. While primarily designed for audio applications, it can be used effectively in RF circuits up to several megahertz.

Handling and Mounting Considerations

Proper handling and mounting are essential to maintain the performance and reliability of the 2N5486:

• Use proper ESD precautions during handling and installation
• For through-hole mounting, lead bending should occur no closer than 3mm from the package body
• When soldering, limit iron temperature to 300°C maximum and exposure time to 10 seconds
• For wave soldering, preheating to 100-110°C is recommended
• In surface mount applications, follow recommended reflow profiles for the specific package type

Reliability and Quality

The 2N5486 meets stringent quality and reliability standards:

• Manufactured under strict process controls
• 100% electrical testing at multiple stages of production
• Compliant with RoHS directives for lead-free applications
• Qualified to applicable industry standards for discrete semiconductors

Alternative Components

When the 2N5486 is not available, these alternatives may be considered:

• 2N5484: Lower I_DSS range (1-5mA)
• 2N5485: Intermediate I_DSS range (2-10mA)
• J201: Similar characteristics in different package
• BF245B: European equivalent with comparable specs