NXP Semiconductors BF1202WR,135

Overview

BF1202WR from NXP Semiconductors is an enhancement-type N-channel dual-gate PoLo MOSFET with source and substrate internally connected, optimized for low-noise VHF/UHF amplifier stages in TV tuners and professional communications equipment. It delivers 30 mS typical forward transfer admittance, 1.7 pF input capacitance at gate 1, 1.1 dB noise figure at 800 MHz, and operates up to 150 °C junction temperature.

For engineers reviewing the BF1202WR datasheet, BF1202WR pinout, BF1202WR application, or BF1202WR equivalent, key selection criteria include its dual-gate AGC capability, cross-modulation performance at 40 dB AGC (100–105 dBµV), thermal resistance of 155 K/W, and SOT343R package compatibility with high-frequency layout requirements.

Technical Context

The BF1202WR uses a short-channel dual-gate structure with integrated protection diodes between each gate and source, enabling robust handling of input voltage surges. Its partly internal self-biasing circuit ensures stable DC operating point and improved cross-modulation performance under automatic gain control conditions.

It operates as a low-noise gain-controlled amplifier with gate 1 serving as RF input and gate 2 as AGC control terminal. The device exhibits 26.5 dB power gain at 800 MHz and maintains sub-2 dB noise figure across 400–800 MHz when biased at ID = 12 mA, VDS = 5 V, VG2-S = 4 V.

Key Specifications

Pinout & Package

BF1202WR is housed in the SOT343R plastic surface-mounted package - a 4-lead reverse-pinned variant with compact 2.2 × 1.35 mm footprint and 0.45 mm pitch, optimized for high-frequency layout and reflow compatibility.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BF1202R, BF1202WR offers superior thermal performance in a smaller footprint, while MRF901 trades dual-gate convenience for higher RF output power and different bias architecture - making BF1202WR optimal for compact, AGC-integrated VHF/UHF receiver front-ends.

Availability

BF1202WR is available at Aetrix Electronics and suitable for digital TV tuners, analog TV IF amplifiers, professional UHF radio receivers, and wireless microphone preamp stages requiring stable component supply and long-term obsolescence management.

Supply support for BF1202WR 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 BF1202WR belongs to NXP's legacy PoLo dual-gate MOSFET product line, engineered specifically for low-noise, AGC-capable VHF/UHF amplifier applications in broadcast and professional wireless equipment.

FAQ

What is the maximum operating junction temperature for BF1202WR?

The BF1202WR has a maximum operating junction temperature of 150 °C, as specified in the Limiting Values table. This rating allows reliable operation in thermally constrained tuner modules and handheld UHF receivers. Derating begins above Ts = 119 °C per the thermal characteristics table, and the device must be mounted with adequate copper pour to maintain Tj ≤ 150 °C under full 200 mW dissipation.

How does BF1202WR differ from BF1202 and BF1202R in package and thermal performance?

The BF1202WR uses the SOT343R package (2.2 × 1.35 mm), while BF1202 uses SOT143B and BF1202R uses SOT143R - both larger at 3.0 × 1.4 mm. BF1202WR's thermal resistance is 155 K/W (junction-to-solder point), lower than BF1202/BF1202R's 185 K/W, enabling better heat dissipation in space-constrained UHF layouts without changing bias or gain performance.

Can BF1202WR be used as a direct replacement for BF1202R in existing designs?

No - BF1202WR has reverse pinning (pin 1 = source, pin 2 = drain, pin 4 = gate 2, pin 3 = gate 1) versus BF1202R's SOT143R pinout (pin 1 = source, pin 2 = drain, pin 4 = gate 1, pin 3 = gate 2). PCB layout revision is required to accommodate the swapped gate terminals, though electrical behavior and biasing remain functionally identical.

What is the typical noise figure of BF1202WR at 400 MHz and how is it measured?

The BF1202WR achieves a typical noise figure of 0.9 dB at 400 MHz under conditions of VDS = 5 V, VG2-S = 4 V, ID = 12 mA, and YS = YS opt (optimum source admittance). This value is measured using calibrated noise-figure analyzers with matched source impedance and confirmed in Table 2 of the datasheet, reflecting its suitability for high-sensitivity UHF receiver front-ends.

Does BF1202WR require external gate protection diodes?

No - the BF1202WR integrates protection diodes between each gate (G1 and G2) and the source terminal, as stated in the DESCRIPTION section. These diodes safeguard against electrostatic discharge and input voltage surges up to ±10 mA gate current limits, eliminating the need for discrete external clamping components in most tuner and receiver applications.