NXP Semiconductors MRF300AN-81MHZ

Overview

MRF300AN-81MHZ from NXP Semiconductors is a reference circuit board designed to evaluate the MRF300AN 300 W RF power LDMOS transistor at 81.36 MHz under CW conditions. It delivers 325 W output power, 25.1 dB power gain, and 77.5% drain efficiency at 50 Vdc supply and 100 mA quiescent drain current. The board supports industrial plasma etching and MRI RF amplifier stages.

For engineers reviewing the MRF300AN-81MHZ datasheet, MRF300AN-81MHZ pinout, MRF300AN-81MHZ application, or MRF300AN-81MHZ equivalent, this reference design provides validated impedance matching (Z_source = 3.86 + j7.90 Ω, Z_load = 4.45 + j3.53 Ω), component-level BOM traceability, and thermal performance data for high-ruggedness HF/VHF amplifier development.

Technical Context

The MRF300AN-81MHZ reference circuit implements a single-ended common-source amplifier using the MRF300AN in Class AB operation. Input and output matching networks are optimized for 50 Ω systems at 81.36 MHz, with measured input return loss of –21 dB at 230 MHz (per general device characterization) and verified load mismatch tolerance up to VSWR >65:1.

It integrates discrete passive components including ATC and Murata chip capacitors, Coilcraft air-core and square inductors (e.g., 0806SQ-12NJL, 0806SQ-19NJL), and Vishay zero-ohm and trimming resistors. The PCB uses FR4 material (0.087″ thickness, ε_r = 4.8, 2 oz copper) with layout documented in Figure 23.

Key Specifications

Availability

MRF300AN-81MHZ is available at Aetrix Electronics and suitable for industrial plasma etching, medical MRI RF subsystems, and broadcast transmitter development requiring stable component supply and proven reference designs.

Supply support for MRF300AN-81MHZ 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 communication markets.

The MRF300AN-81MHZ belongs to NXP's RF Power LDMOS Transistor reference circuit family, engineered to accelerate robust HF/VHF amplifier design for industrial heating, scientific instrumentation, and broadcast infrastructure.

FAQ

What is the MRF300AN-81MHZ used for?

The MRF300AN-81MHZ is a dedicated reference circuit board for evaluating the MRF300AN RF power transistor at 81.36 MHz. It enables rapid prototyping of high-efficiency, high-ruggedness amplifiers in industrial plasma generation, MRI excitation systems, and HF communications transmitters. The board validates thermal performance, impedance matching, and reliability under continuous-wave operation.

Does the MRF300AN-81MHZ include the MRF300AN transistor?

Yes, the MRF300AN-81MHZ reference circuit includes one MRF300AN RF power LDMOS transistor mounted on the board. The transistor is soldered in TO-247-3L package with pin 1 = Gate, pin 2 = Source, pin 3 = Drain, and the exposed backside serving as an additional source terminal per NXP documentation.

What are the key passive components on the MRF300AN-81MHZ board?

The MRF300AN-81MHZ board uses ATC and Murata high-Q RF capacitors (e.g., 4700 pF, 120 pF, 47 pF), Coilcraft square and air-core inductors (0806SQ-12NJL, 0806SQ-19NJL, 1212VS-111MEB), and Vishay precision resistors including zero-ohm jumpers and 5 kΩ multi-turn trimmers for gate bias adjustment - all selected for stability at 81.36 MHz.

Can the MRF300AN-81MHZ be used at frequencies other than 81.36 MHz?

The MRF300AN-81MHZ is specifically tuned for optimal performance at 81.36 MHz. While the underlying MRF300AN transistor operates from 1.8–250 MHz, this board's matching network, layout, and component values are not broadband; operation outside ±1 MHz requires re-tuning or use of another variant (e.g., MRF300AN-50MHZ or MRF300AN-144MHZ).

Is thermal management addressed on the MRF300AN-81MHZ board?

Yes - the MRF300AN-81MHZ board is designed for integration with external heatsinking via the TO-247-3L package's metal tab and exposed backside (which serves as a source terminal). Its layout follows NXP's thermal guidelines, and the 0.087″ FR4 PCB with 2 oz copper supports heat spreading. Full thermal validation is provided in the datasheet for case temperature ≤76°C at 300 W CW.