NXP Semiconductors BF1101WR,115

Overview

BF1101WR from NXP Semiconductors is an enhancement-type N-channel dual-gate MOSFET with source and substrate internally connected, designed for low-noise RF amplification up to 1 GHz. It features 30 mS typical forward transfer admittance, 2.2 pF input capacitance at gate 1, and 1.7 dB typical noise figure at 800 MHz - optimized for VHF/UHF tuner front-ends in television and professional communications equipment.

For engineers reviewing the BF1101WR datasheet, BF1101WR pinout, BF1101WR application, or BF1101WR equivalent, this page delivers verified package mapping (SOT343R), validated dual-gate biasing behavior, confirmed cross-modulation performance (100 dBµV at 40 dB AGC), and real-world RF gain stability under AGC control - all critical for high-selectivity RF amplifier design.

Technical Context

The BF1101WR employs a short-channel dual-gate structure where gate 1 serves as RF input and gate 2 as AGC-controlled bias node, enabling precise gain reduction without degrading noise or linearity. Its integrated gate-source diodes provide surge protection, while internal source-substrate connection simplifies bias network design in common-source configurations.

Operation requires V_DS ≤ 7 V and I_D ≤ 30 mA, with gate 1 threshold voltage ranging 0.3–1.0 V and gate 2 threshold 0.3–1.2 V at T_j = 25 °C. Cross-modulation performance is specified at 100 dBµV input level for k = 1% distortion under 40 dB AGC - confirming suitability for high-dynamic-range signal paths.

Key Specifications

Pinout & Package

SOT343R plastic surface-mounted package (4 leads, reverse pinning); dimensions: 2.2 × 1.35 × 0.9 mm (L × W × H), thermal resistance R_{th j-s} = 200 K/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BF1101R, BF1101WR offers identical RF parameters but in a smaller SOT343R package with distinct pin numbering - requiring PCB redesign. Against BF998, BF1101WR trades 13 mS lower |y_fs| and +0.4 dB higher noise for proven reliability in mature TV tuner production lines.

Availability

BF1101WR is available at Aetrix Electronics and suitable for television tuner front-ends, professional UHF transceiver LNAs, RF signal generator output stages, and test equipment IF amplifiers requiring stable component supply across long-lifecycle consumer and industrial programs.

Supply support for BF1101WR 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 specializing in high-performance RF, analog, and mixed-signal solutions for automotive, industrial, and consumer applications.

The BF1101WR belongs to NXP's legacy dual-gate MOSFET product line, engineered specifically for low-noise, AGC-stable RF amplification in VHF/UHF tuner and communications systems operating between 30 MHz and 1 GHz.

FAQ

What is the maximum drain-source voltage rating for BF1101WR?

The BF1101WR has a maximum drain-source voltage (V_DS) rating of 7 V, as defined in its Absolute Maximum Ratings table. This limit applies under all operating conditions and must not be exceeded to prevent permanent device damage. Operation at V_DS = 5 V is typical in tuner applications, providing 2 V headroom for transient spikes. The BF1101WR datasheet confirms this value is consistent across static and dynamic characterization conditions.

Does BF1101WR require external gate protection diodes?

No, the BF1101WR integrates diodes between each gate and source, providing built-in protection against electrostatic discharge and input voltage surges up to ±10 mA. This eliminates the need for external clamping diodes in standard TV tuner and communications equipment designs. The internal diodes are explicitly documented in the "Description" section of the BF1101WR datasheet and validated in the limiting values for gate current (±10 mA).

How does BF1101WR achieve stable cross-modulation performance during AGC?

The BF1101WR achieves stable cross-modulation performance through a partly internal self-biasing circuit that maintains DC operating point integrity during AGC voltage changes on gate 2. This design ensures Xmod remains at 100 dBµV even at 40 dB AGC, as measured per the test setup in Figure 21. The BF1101WR's gate 2 threshold voltage range (0.3–1.2 V) and controlled transconductance roll-off enable predictable gain reduction without introducing distortion.

What is the thermal resistance from junction to soldering point for BF1101WR?

The BF1101WR has a thermal resistance from junction to soldering point (R_{th j-s}) of 200 K/W, as specified in the Thermal Characteristics section. This value reflects heat dissipation through the source lead to the PCB copper, and directly informs derating curves - e.g., total power dissipation drops to zero at Ts = 110 °C. The BF1101WR's SOT343R package geometry and leadframe construction determine this thermal path, and it is validated in the power derating curve (Figure 4).

Can BF1101WR be used in place of BF1101 or BF1101R without layout changes?

No, BF1101WR cannot replace BF1101 or BF1101R without PCB layout changes. While all three share identical electrical specifications, BF1101WR uses the SOT343R package with reverse pinning (pin 2 = source, pin 1 = drain, pin 4 = gate 2, pin 3 = gate 1), whereas BF1101R uses SOT143R (pin 1 = source, pin 2 = drain, pin 3 = gate 2, pin 4 = gate 1) and BF1101 uses SOT143B (pin 1 = source, pin 2 = drain, pin 3 = gate 2, pin 4 = gate 1). The BF1101WR's smaller footprint and inverted pin order require dedicated land patterns.