NXP Semiconductors BF1218,115

Overview

BF1218,115 from NXP Semiconductors is a dual N-channel dual-gate MOSFET amplifier IC with integrated AGC switch, housed in a SOT363 package. It integrates two low-noise amplifiers (A and B) sharing source and gate2 leads, where amplifier B's gate1 controls an internal switch to enable gain control. Key confirmed specs include 31 mS forward transfer admittance (amp A), 0.9 dB noise figure at 400 MHz (amp A), 105 dBµV cross modulation at 40 dB AGC, 6 V drain-source voltage rating, and 180 mW total power dissipation.

For engineers reviewing the BF1218,115 datasheet, BF1218,115 pinout, BF1218,115 application, or BF1218,115 equivalent, this device is selected for VHF/UHF gain-controlled LNA stages requiring stable AGC performance, minimal external bias components, and ESD-protected dual-gate architecture in space-constrained tuner designs.

Technical Context

The BF1218,115 implements a dual-gate MOSFET topology with physically shared source and gate2 terminals across both amplifiers, enabling compact integration and inter-amplifier coupling. Its internal switch is directly controlled by gate1 bias of amplifier B, allowing seamless AGC state transitions without external switching circuitry.

DC stabilization is achieved via on-die bias circuits, while integrated gate-source diodes provide surge protection. The device operates with 5 V supply and delivers superior cross-modulation suppression-measured at 105 dBµV under 40 dB AGC-due to optimized channel design and substrate-source interconnection.

Key Specifications

Pinout & Package

The BF1218,115 is supplied in a plastic surface-mounted SOT363 (SC-88) package measuring 2.2 mm × 1.8 mm × 1.1 mm, with 0.65 mm lead pitch and gull-wing leads suitable for reflow soldering.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-gate MOSFET amplifier applications.

Compared with BF998,115 and MRF901, the BF1218,115 uniquely integrates dual amplifiers with shared bias nodes and an AGC-driven switch in one SOT363 package-enabling true single-chip gain-controlled LNA functionality without layout compromises or BOM expansion.

Availability

BF1218,115 is available at Aetrix Electronics and suitable for digital television tuners, professional UHF receivers, and analog TV front-end upgrades requiring stable component supply, ESD-hardened RF performance, and compact dual-amplifier integration.

Supply support for BF1218,115 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

NXP Semiconductors is a global semiconductor company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and consumer markets.

The BF1218,115 belongs to NXP's RF transistor product line, engineered specifically for high-linearity, low-noise VHF/UHF amplifier applications in broadcast and communication equipment where AGC integration and space efficiency are critical.

FAQ

What is the maximum drain-source voltage rating for the BF1218,115?

The BF1218,115 has a maximum drain-source voltage (V_DS) rating of 6 V DC, as specified in the Absolute Maximum Ratings table. This allows safe operation with standard 5 V supply rails while maintaining margin for transient spikes. Exceeding this voltage risks permanent damage to the dual-gate MOSFET structure.

How does the integrated switch in the BF1218,115 operate?

The integrated switch in the BF1218,115 is controlled exclusively by the gate1 bias voltage applied to amplifier B (pin 3). When V_G1B rises to ~5 V, amplifier B turns on and simultaneously disables amplifier A by pulling its gate1 (pin 1) toward ground through internal circuitry-enabling seamless AGC state transition without external components.

Can the BF1218,115 be used in both VHF and UHF frequency bands?

Yes, the BF1218,115 is characterized for operation across both VHF (e.g., 110–250 MHz) and UHF (e.g., 400–1000 MHz) bands. Its noise figure remains ≤1.7 dB up to 800 MHz, and transducer power gain exceeds 24 dB at 800 MHz, making it suitable for DTV tuners covering 470–862 MHz and analog TV systems spanning 45–860 MHz.

What is the thermal resistance from junction to solder point for the BF1218,115?

The BF1218,115 has a typical thermal resistance from junction to solder point (R_th(j-sp)) of 225 K/W, measured under standard SMT reflow conditions. This value assumes proper PCB copper pour under the exposed source pad (pin 5) and dictates maximum allowable power dissipation of 180 mW at T_sp ≤109 °C.

Is the BF1218,115 ESD-sensitive, and what precautions are required?

Yes, the BF1218,115 is explicitly marked as ESD-sensitive in its datasheet. Handling requires compliance with IEC 61340-5-1:2016-using grounded wrist straps, conductive foam storage, and ESD-safe workstations. Gate terminals (pins 1, 2, 3) are especially vulnerable due to thin oxide layers; uncontrolled discharge can degrade y_fs or increase noise figure irreversibly.