BF1211WR,115

Overview

The BF1211WR,115 is an N-channel dual-gate MOS-FET from NXP Semiconductors, housed in a SOT343R plastic surface-mounted package. It features a drain-source voltage of 6 V, a continuous drain current of 30 mA, and a total power dissipation of 180 mW. The device exhibits a forward transfer admittance ranging from 25 to 40 mS and an input capacitance at gate 1 between 2.1 and 2.6 pF. Noise figure performance varies with frequency, reaching 0.9 dB at 400 MHz and 1.3 dB at 800 MHz under optimal source admittance conditions.

Feature Summary

• Dual-gate architecture providing low noise gain controlled amplifier capabilities for VHF and UHF applications.
• Integrated internal self-biasing circuitry ensures stable DC operation and minimizes cross-modulation distortion during automatic gain control adjustments.
• Short channel transistor design delivers a high ratio of forward transfer admittance to input capacitance.
• Internal integrated diodes between gates and source protect the component against excessive input voltage surges.

Applications

• Gain controlled low noise amplifiers
• VHF and UHF amplifiers
• 5 V digital television tuner applications
• 5 V analog television tuner applications

Procurement Notes

Verify the specific ordering suffix

Selection Notes

Select this component when designing low-noise RF front-ends requiring independent gain control via the second gate. Ensure the operating environment stays within the specified junction temperature limits and that the 6 V drain-source voltage rating is not exceeded. Consider the SOT343R package dimensions for PCB layout constraints and verify thermal resistance requirements for the specific mounting conditions.

Part Context

This part belongs to the BF1211 series of N-channel dual-gate MOS-FETs, which includes variants like the BF1211 and BF1211R. These devices are enhancement type field-effect transistors designed for radio frequency applications. The series shares core electrical characteristics but differs in packaging and pinning configurations to suit various board space and routing requirements.

Replacement Considerations

Consult official documentation for direct substitutes. The BF1211R offers reverse pinning in an SOT143R package, while the standard BF1211 uses an SOT143B package. Verify pin compatibility and thermal characteristics before substituting.

FAQ

How does the BF1211WR handle input voltage surges?

The device incorporates integrated diodes between the gates and the source to protect against excessive input voltage surges.

What is the purpose of the second gate on this MOS-FET?

The second gate enables gain control functionality, allowing the device to operate as a low noise gain controlled amplifier suitable for AGC applications.

Does the BF1211WR include self-biasing features?

Yes, it contains a partly internal self-biasing circuit designed to ensure good cross-modulation performance during AGC and provide good DC stabilization.