NXP Semiconductors BF1101,215

Overview

BF1101,215 from NXP Semiconductors is an enhancement-type N-channel dual-gate MOSFET designed for RF amplification in VHF/UHF tuner front-ends. It features 30 mS typical forward transfer admittance, 2.2 pF input capacitance at gate 1, 1.7 dB noise figure at 800 MHz, and operates with 3–7 V supply voltage. Its integrated gate-source diodes provide surge protection, and internal partial self-biasing ensures stable cross-modulation performance under AGC control.

For engineers reviewing the BF1101,215 datasheet, BF1101,215 pinout, BF1101,215 application, or BF1101,215 equivalent, key selection criteria include its dual-gate architecture for gain control, low-noise RF performance up to 1 GHz, SOT143B package compatibility, and suitability for television tuner and professional communications receiver designs requiring high yfs/Cig1 ratio and DC-stable AGC operation.

Technical Context

The BF1101,215 employs a short-channel dual-gate structure where gate 1 serves as the RF input and gate 2 as the AGC control terminal. Its source and substrate are internally connected, and integrated diodes between each gate and source protect against input voltage transients.

It delivers 25–40 mS forward transfer admittance (|yfs|) at ID = 12 mA, VDS = 5 V, and exhibits 25–35 fF reverse transfer capacitance (Crss) at 1 MHz - critical for minimizing feedback and ensuring stability in broadband amplifier stages operating up to 1 GHz.

Key Specifications

Pinout & Package

The BF1101,215 is housed in the SOT143B plastic surface-mounted package (4 leads), with dimensions per JEDEC outline: D = 2.8–3.0 mm, E = 1.2–1.4 mm, body height A = 0.9–1.1 mm. Pin 1 is source, Pin 2 is drain, Pin 3 is gate 2, and Pin 4 is gate 1 - confirmed by Fig.1 and marking code "NDp".

Key Features

Applications

Equivalent & Alternatives

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

Compared with BF1101R,215 and BF1101WR,215, the BF1101,215 offers direct SOT143B compatibility with standard pin 1–4 mapping (source–drain–gate2–gate1), eliminating layout changes while delivering identical RF gain, noise, and AGC linearity - making it the default choice for new VHF/UHF tuner designs.

Availability

BF1101,215 is available at Aetrix Electronics and suitable for television tuner front-ends, professional UHF receivers, and VHF aircraft band communication equipment requiring stable component supply and long-term obsolescence management.

Supply support for BF1101,215 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 consumer, industrial, and communications markets.

The BF1101,215 belongs to NXP's legacy RF transistor product line, engineered specifically for low-noise, dual-gate VHF/UHF amplification in broadcast and professional radio equipment where AGC stability and ESD resilience are essential.

FAQ

What is the maximum drain-source voltage rating for BF1101,215?

The BF1101,215 has a maximum drain-source voltage (V_DS) rating of 7 V, as specified in the Limiting Values table. This rating applies under all operating conditions and must not be exceeded to prevent permanent device damage. The BF1101,215 is intended for use in low-voltage RF amplifier stages, typically biased at 5 V, making this 7 V ceiling sufficient for transient margin in tuner applications.

Does BF1101,215 require external biasing resistors for gate 1 and gate 2?

Yes, the BF1101,215 requires external biasing: gate 1 (pin 4) is typically connected through a resistor (e.g., 120 kΩ) to a fixed V_GG supply, while gate 2 (pin 3) receives the AGC control voltage. Figure 21 in the datasheet shows the standard test setup with R_G1, and typical operating points (e.g., V_G2-S = 4 V, I_D = 12 mA) assume these external networks. The BF1101,215 includes partial internal self-biasing but relies on external components for stable DC operating point control.

What is the noise figure of BF1101,215 and at what frequency is it specified?

The BF1101,215 has a typical noise figure (F) of 1.7 dB at 800 MHz, measured under conditions of V_DS = 5 V, V_G2-S = 4 V, I_D = 12 mA, and Y_S = Y_{S opt}. This value is confirmed in both the Quick Reference Data and Dynamic Characteristics tables. The BF1101,215 maintains sub-2.5 dB noise figure across 500–1000 MHz, supporting high-sensitivity reception in UHF TV and communications bands.

Is BF1101,215 pin-compatible with BF1101R,215 or BF1101WR,215?

No, the BF1101,215 is not pin-compatible with BF1101R,215 or BF1101WR,215. While all three share identical electrical specifications, BF1101R,215 uses SOT143R with reversed pinout (pins 3 and 4 swapped), and BF1101WR,215 uses the smaller SOT343R package with different mechanical dimensions. The BF1101,215 uses SOT143B with standard pin 1 = source, 2 = drain, 3 = gate 2, 4 = gate 1 - requiring unique PCB layout.

What protective features does BF1101,215 include against ESD or input overvoltage?

BF1101,215 integrates diodes between each gate (gate 1 and gate 2) and the source terminal to clamp excessive input voltage surges - a key protection feature explicitly stated in the Description section. Additionally, it is supplied in anti-static packaging per the CAUTION note. These diodes limit gate-source voltage to ~1.5 V forward drop, safeguarding the fragile gate oxide during handling and in-circuit transients. No external TVS or series resistors are required solely for basic ESD protection in typical tuner applications.