2N3820

Overview

The onsemi 2N3820 is a P-channel general-purpose JFET designed for low-level audio and high-impedance signal source applications. It features a Drain-Gate Voltage of -20 V and a Gate-Source Voltage of 20 V, with a maximum total device dissipation of 350 mW at 25°C. The zero-gate voltage drain current ranges from -0.3 to -15 mA at -10 V. Small-signal characteristics include an input capacitance of 32 pF and a reverse transfer capacitance of 16 pF at 1.0 kHz. The device operates within a junction temperature range up to 150°C and utilizes a TO-92 package.

Feature Summary

• P-channel JFET configuration optimized for high-impedance signal sources
• Designed primarily for low-level audio and general-purpose amplifier applications
• Capable of handling small-signal operations with defined forward transfer conductance

Applications

• Low-level audio amplification circuits
• General-purpose amplifier stages
• High-impedance signal source buffering

Procurement Notes

Verify the specific manufacturer origin, as the component was originally produced by Fairchild Semiconductor and may now be distributed under onsemi branding. Confirm the package type matches the required TO-92 footprint and pinout configuration (Drain, Gate, Source) before integration into the design. Ensure compliance with RoHS standards if applicable to the final assembly requirements.

Selection Notes

Select this component when a P-channel JFET is required for low-noise, high-impedance input stages. The 350 mW power dissipation rating limits its use to small-signal applications rather than power switching. Consider the thermal resistance values if operating in enclosed environments without adequate heat sinking or airflow.

Part Context

The 2N3820 belongs to the family of P-channel Junction Field-Effect Transistors commonly used in analog signal processing. Originally manufactured by Fairchild Semiconductor, it serves as a standard discrete semiconductor solution for pre-amplification tasks where high input impedance and low distortion are critical performance factors.

Replacement Considerations

Check for direct cross-reference equivalents such as the 2N5485 or similar P-channel JFETs with matching voltage ratings and TO-92 packaging. Verify that substitute devices meet the same electrical specifications for gate-source breakdown voltage and drain current to ensure circuit compatibility.