BF998R,235

Overview

The BF998R,235 is an N-channel dual-gate MOSFET designed for UHF band RF small-signal applications. Manufactured by NXP Semiconductors, this silicon device operates as a depletion-mode field-effect transistor with a tetrode structure. It is housed in the SOT-143B surface-mount package, featuring four pins. The component supports a maximum drain-source voltage of 12 V and a continuous drain current of 30 mA. With a power dissipation rating of 200 mW, it functions within a temperature range of -65 °C to +150 °C. The part complies with RoHS standards and contains no SVHC.

Feature Summary

• Dual-gate architecture providing high isolation between input and output ports
• Depletion-mode operation suitable for low-noise amplification
• Integrated ESD protection mechanisms for enhanced reliability
• Compact SOT-143B surface-mount packaging for automated assembly

Applications

• UHF band radio frequency amplification stages
• Low-noise amplifier (LNA) circuits in communication systems
• Mixers and frequency converters in RF front-ends
• Signal processing in portable wireless devices

Procurement Notes

Verify the specific ordering code BF998R,235 against official NXP documentation to confirm tape-and-reel quantity and suffix definitions. Ensure compatibility with existing PCB footprints for the SOT-143B package. Cross-reference electrical parameters with current datasheets to validate performance requirements for your specific RF application design.

Selection Notes

Select this component for designs requiring a dual-gate MOSFET in a compact surface-mount form factor. The UHF band optimization makes it suitable for frequencies typically ranging from 30 MHz to 300 MHz. Consider the 12 V breakdown voltage and 200 mW thermal limits when designing biasing networks and heat dissipation strategies for high-frequency signal paths.

Part Context

This device belongs to NXP's portfolio of RF discrete semiconductors, specifically focusing on silicon-based field-effect transistors. The BF998 series is historically significant in UHF communications, offering a balance of gain and noise figure. The 'R' suffix often denotes specific reel packaging or variant configurations within the manufacturer's catalog, while '235' indicates the specific orderable unit configuration.

Replacement Considerations

Potential substitutes include the BF998W from Infineon or Siemens, which shares similar silicon N-channel tetrode characteristics. Verify pinout compatibility and electrical specifications such as gate-source threshold voltage and capacitance values before substitution. Consult official cross-reference guides for approved equivalents.