BF1218,115

Overview

The BF1218 is a dual N-channel dual gate MOSFET amplifier housed in a SOT363 micro-miniature plastic package. It integrates two amplifiers with shared source and gate2 leads, plus an internal switch controlled by amplifier B's gate1 bias. Key electrical parameters include a drain-source voltage of 6 V, drain current of 30 mA, and total power dissipation of 180 mW. Forward transfer admittance reaches up to 41 mS for amplifier A and 40 mS for amplifier B at 100 MHz. Noise figures are typically 0.9 dB at 400 MHz and 1.4 dB at 800 MHz.

Feature Summary

• Combines two low noise gain controlled amplifiers in a single package, one with fully integrated bias and the other partly integrated.
• Features an internal switch operated by the gate1 bias of amplifier B to reduce external component count.
• Provides superior cross modulation performance during Automatic Gain Control (AGC) operations.
• Offers high forward transfer admittance and a high ratio of forward transfer admittance to input capacitance.

Applications

• Gain controlled low noise amplifiers for VHF and UHF applications
• Digital and analog television tuners
• Professional communication equipment

Procurement Notes

Verify the specific ordering suffix matches the required package variant, as standard listings may vary. Confirm the device status on the manufacturer website, as product availability can change. Ensure ESD precautions are strictly followed during handling due to device sensitivity. Cross-reference the marking code M7 with the physical component to authenticate the part before integration into production designs.

Selection Notes

Select this component when designing compact RF front-ends requiring dual amplification paths within a minimal footprint. The integrated switch functionality simplifies circuit topology by eliminating external switching components. Evaluate the noise figure and admittance specifications against system requirements for VHF and UHF bands. Consider the thermal resistance characteristics for heat dissipation planning in dense PCB layouts.

Part Context

This discrete semiconductor device belongs to the category of dual gate MOSFETs designed for radio frequency applications. It serves as a fundamental building block for signal conditioning stages in broadcast and communication hardware. The technology leverages silicon-based field-effect transistor architecture optimized for linearity and gain control in analog signal processing chains.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.

FAQ

How is the internal switch in the BF1218 controlled?

The integrated switch is operated by the gate1 bias of amplifier B.

What is the maximum drain-source voltage rating for the BF1218?

The maximum DC drain-source voltage is 6 V.

Does the BF1218 include protection against input voltage surges?

Yes, integrated diodes between the gates and source protect against excessive input voltage surges.