CMPF5485 TR

Overview

The CMPF5485 TR is a surface-mount N-channel silicon JFET designed for RF amplifier and mixer applications in the VHF/UHF frequency range. It operates within a drain current of up to 30 mA and dissipates 350 mW at 25°C. Key electrical parameters include a gate-source cutoff voltage (VGS(off)) ranging from 0.5 V to 4.0 V, and a zero-gate voltage drain current (IDSS) between 4.0 mA and 10 mA. The device features a maximum gate-drain voltage of 25 V and exhibits low input capacitance (Ciss) of 5.0 pF at 1.0 MHz. Noise figure (NF) is typically 2.5 dB at 1.0 kHz and 2.0 dB at 100 MHz with specific biasing conditions.

Feature Summary

• Optimized for high-frequency operation in VHF and UHF bands
• Low noise figure suitable for sensitive RF front-end stages
• Interchangeable source and drain terminals in SOT-23 package

Applications

• RF amplifiers
• Mixers
• Analog switches

Procurement Notes

Verify the ordering suffix against manufacturer specifications before purchase. The suffix PBFREE indicates lead-free plating compliance, while TIN/LEAD denotes traditional plating options. Confirm that the reel packaging matches the required quantity for production runs. Ensure the component meets RoHS environmental substance directives if applicable to the target market regulations.

Selection Notes

Select the CMPF5485 when a moderate IDSS range of 4.0 mA to 10 mA is required for impedance matching or gain control. Compare its noise figure and forward transconductance against the CMPF5484 and CMPF5486 variants to ensure alignment with specific circuit sensitivity requirements. Verify that the SOT-23 thermal resistance of 357 °C/W supports the intended power dissipation levels in the final assembly.

Part Context

This component belongs to the Central Semiconductor CMPF5484 series, which includes three distinct part numbers differentiated by their pinch-off voltage and drain current characteristics. All members share the same physical SOT-23 footprint and electrical limits but offer varying performance curves for different RF design needs. The series utilizes Process 50 technology to achieve consistent reliability across the product line.

Replacement Considerations

Direct functional substitutes within the same family include the CMPF5484 and CMPF5486. These parts share identical pinouts and maximum ratings but differ in VGS(off) and IDSS ranges. Cross-manufacturer replacements require careful verification of Y-parameters and noise figures at operating frequencies to maintain circuit stability.