J309G

Overview

The J309G is an N-channel depletion-mode Junction Field-Effect Transistor (JFET) designed for VHF and UHF amplifier applications. It features a TO-92 (CASE 29-11) package with Style 5 pin configuration: Pin 1 Drain, Pin 2 Source, Pin 3 Gate. Key electrical parameters include a Drain-Source Voltage (VDS) of 25 Vdc and a Gate-Source Voltage (VGS) of 25 Vdc. The Zero-Gate-Voltage Drain Current (IDSS) ranges from 12 mA to 30 mA at VDS = 10 Vdc. At 100 MHz, the Common-Gate Power Gain (Gpg) is typically 16 dB, and the Forward Transconductance (Re(yfs)) is typically 12 mmhos.

Feature Summary

• Designed specifically for high-frequency VHF and UHF amplifier circuits.
• Utilizes a standard TO-92 plastic package suitable for cost-sensitive mass production.
• Offers low noise performance and high dynamic range characteristics.

Applications

• UHF and VHF amplifiers
• Mixers
• Oscillators

Procurement Notes

Verify the ordering suffix 'G' indicates a Pb-Free package as per onsemi documentation. Confirm the specific pin style (Style 5) matches the target circuit design. Ensure compliance with RoHS directives if required by the end application. Check for any specific handling precautions related to the TO-92 lead frame construction during assembly.

Selection Notes

Select this component when a low-noise N-channel JFET is required for frequencies up to the UHF band. Compare IDSS ranges against circuit biasing requirements. Evaluate the typical 16 dB power gain at 100 MHz against system link budget needs. Consider the TO-92 package constraints for thermal dissipation in enclosed environments.

Part Context

The J309G belongs to the J309/J310 family of N-channel depletion JFETs manufactured by onsemi. It serves as a preferred device choice for RF signal processing stages. The 'G' suffix denotes environmental compliance, specifically Pb-Free packaging, distinguishing it from older non-compliant variants while maintaining identical electrical specifications.

Replacement Considerations

Public datasheets list the J309 as a direct replacement for discontinued Siliconix J309 units. Verify pinout compatibility (Drain-Source-Gate) when substituting. No other specific cross-reference part numbers are confirmed in the provided source material.

FAQ

What is the pin configuration for the J309G?

The J309G uses TO-92 Style 5 pinout: Pin 1 is Drain, Pin 2 is Source, and Pin 3 is Gate.

What is the typical forward transconductance at 100 MHz?

The typical Common-Source Forward Transconductance Re(yfs) is 12 mmhos at VDS = 10 Vdc, ID = 10 mAdc, and f = 100 MHz.

Does the J309G support lead-free soldering processes?

Yes, the 'G' suffix indicates that the device is available in Pb-Free packages compliant with onsemi's environmental strategy.