NXP Semiconductors BF1201WR,135

Overview

BF1201WR from NXP Semiconductors is an enhancement-type N-channel dual-gate PoLo MOSFET with source and substrate internally connected, designed for low-noise RF amplification in VHF/UHF tuners. It delivers 28 mS typical forward transfer admittance, 2.6 pF input capacitance at gate 1, and 1 dB noise figure at 400 MHz, operating from 3–9 V supply in digital/analogue TV tuner front-ends.

For engineers reviewing the BF1201WR datasheet, BF1201WR pinout, BF1201WR application, or BF1201WR equivalent, key selection criteria include its dual-gate AGC capability, cross-modulation performance (105 dBµV at 40 dB AGC), thermal resistance (155 K/W), and SOT343R package compatibility with high-frequency layout constraints.

Technical Context

The BF1201WR uses a short-channel PoLo (Polarity Logic) structure enabling high y_fs/C_ig1-ss ratio for optimized gain-noise trade-off. Its dual-gate architecture allows independent DC biasing of gate 2 (V_G2-S = 4 V typical) while gate 1 serves as RF input with integrated protection diodes.

Internal partial self-biasing stabilizes DC operating point under AGC conditions, ensuring consistent cross-modulation performance across gain reduction ranges. The device exhibits pulsed y_fs of 23–35 mS and reverse transfer capacitance (C_rss) of 15–30 fF at 1 MHz, supporting stable wideband amplification up to 1 GHz.

Key Specifications

Pinout & Package

BF1201WR is housed in the SOT343R plastic surface-mount package (4 leads, reverse pinning), measuring 2.2 × 1.35 × 0.9 mm with 0.65 mm lead pitch. This ultra-compact outline minimizes parasitic inductance for UHF operation and supports automated placement in space-constrained tuner modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BF1201WR, the BF1201R and BF1201 share identical RF performance but differ in package thermal resistance and pin orientation-BF1201WR's SOT343R offers superior power density and thermal efficiency for next-generation miniaturized tuners, while BF1201R/BF1201 provide mechanical compatibility with established layouts.

Availability

BF1201WR is available at Aetrix Electronics and suitable for digital television tuners, professional UHF receivers, and FM radio preselectors requiring stable component supply, long-term obsolescence management, and RoHS-compliant sourcing.

Supply support for BF1201WR 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 leader specializing in high-performance RF, analog, and mixed-signal solutions for consumer, communications, and industrial markets.

The BF1201WR belongs to NXP's legacy PoLo MOSFET product line, engineered specifically for low-noise, high-gain VHF/UHF amplification in broadcast tuner applications with stringent AGC and cross-modulation requirements.

FAQ

What is the maximum drain-source voltage rating for BF1201WR?

The BF1201WR has a maximum drain-source voltage (V_DS) rating of 10 V, as specified in the Absolute Maximum Ratings table. This limit must not be exceeded under any operating condition-including transients-to prevent permanent device damage. Operation at V_DS = 5 V is typical in tuner applications to ensure margin and reliability.

How does BF1201WR achieve low cross-modulation in AGC applications?

The BF1201WR achieves low cross-modulation through partly internal self-biasing that stabilizes the DC operating point during automatic gain control transitions. At 40 dB AGC, it delivers 105 dBµV cross-modulation performance-verified in the datasheet's Quick Reference Data-ensuring minimal inter-channel interference in multi-signal broadcast environments.

What is the thermal resistance of BF1201WR and how does it affect PCB layout?

The BF1201WR has a thermal resistance from junction to soldering point (R_{th j-s}) of 155 K/W. This value requires careful attention to copper pour area and via count under the source pad (Pin 1) to maintain T_j ≤ 150 °C at full 200 mW dissipation. Use ≥ 20 mm² exposed copper with ≥ 4 thermal vias for optimal heat extraction.

Can BF1201WR replace BF1201 in an existing design?

No, BF1201WR cannot directly replace BF1201 due to reverse pinning in the SOT343R package versus standard pinning in BF1201's SOT143B. Pin 3 and Pin 4 are swapped between packages. Layout redesign or adapter board is required; electrical parameters are identical, but mechanical fit is incompatible without modification.

What is the noise figure of BF1201WR at 800 MHz and how is it measured?

The BF1201WR exhibits a noise figure of 1.9–2.5 dB at 800 MHz, measured under conditions of V_DS = 5 V, V_G2-S = 4 V, I_D = 15 mA, and Y_S = Y_{S opt} (optimum source admittance). This data appears in the Dynamic Characteristics table on page 4 of the datasheet and reflects its suitability for UHF receiver front-ends.