NXP Semiconductors MRF1K50H-81MHZ

Overview

MRF1K50H-81MHZ from NXP Semiconductors is a high-ruggedness, 50 V, 1500 W CW RF power LDMOS transistor optimized for narrowband operation at 81.36 MHz in industrial, broadcast, and aerospace transmitters. It delivers 1400 W output power, 23.0 dB power gain, and 75.0% drain efficiency under CW conditions with 150 mA quiescent current. Its dual-gate/dual-drain structure supports push–pull configurations in high-VSWR HF/VHF amplifiers.

For engineers reviewing the MRF1K50H-81MHZ datasheet, MRF1K50H-81MHZ pinout, MRF1K50H-81MHZ application, or MRF1K50H-81MHZ equivalent, this page provides verified performance data from NXP's 81.36 MHz narrowband reference circuit (Table 9), ruggedness validation at 230 MHz, thermal impedance specs, ESD protection class ratings, and layout-critical package interface details - all specific to the MRF1K50H-81MHZ variant.

Technical Context

The MRF1K50H-81MHZ is a laterally diffused MOSFET with enhanced avalanche energy absorption, rated for continuous junction temperatures up to +225°C and characterized across 30–50 V operating voltage range. Its unmatched input/output design enables stable broadband use from 1.8–500 MHz, but the -81MHZ suffix denotes qualification and reference-circuit optimization specifically at 81.36 MHz.

This variant operates in enhancement-mode with gate threshold voltage of 1.7–2.7 Vdc and exhibits low thermal resistance (0.10 °C/W junction-to-case under CW conditions). It features integrated ESD protection meeting HBM Class 2 (2500 V), MM Class B (250 V), and CDM Class IV (2000 V), supporting robust Class C linear amplifier designs in high-reliability RF systems.

Key Specifications

Pinout & Package

Package: NI-1230H-4S - ceramic/metal air-cavity package with source-connected backside flange, designed for high-power RF thermal management and low-inductance grounding. Dimensions per NXP drawing (p.19–21).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RF power amplifier applications.

Compared with MRF1K50N and MRFE6VP61K25H, the MRF1K50H-81MHZ uniquely combines 81.36 MHz narrowband validation, 1400 W CW output, and 75% efficiency in a ruggedized air-cavity package - making it the only option qualified for HF industrial heating and legacy broadcast upgrades requiring exact 81 MHz center-frequency compliance.

Availability

MRF1K50H-81MHZ is available at Aetrix Electronics and suitable for industrial heating systems, HF broadcast transmitters, VHF omnidirectional range (VOR) beacons, and particle accelerator RF cavities requiring stable component supply over extended production lifecycles.

Supply support for MRF1K50H-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 leader specializing in secure connectivity solutions for automotive, industrial, and communications markets, with deep expertise in RF power technology inherited from Freescale.

The MRF1K50H-81MHZ belongs to NXP's high-ruggedness LDMOS transistor family, engineered specifically for mission-critical RF amplification in industrial, scientific, medical, broadcast, and aerospace systems demanding >65:1 VSWR tolerance and 15-year supply assurance.

FAQ

What is the maximum continuous output power of the MRF1K50H-81MHZ at 81.36 MHz?

The MRF1K50H-81MHZ delivers 1400 W CW output power at 81.36 MHz under NXP's validated narrowband reference circuit conditions: VDD = 50 Vdc, IDQ(A+B) = 150 mA, Pin = 3 W. This value is confirmed in Table 9 (p.11) of the official datasheet and reflects real-world performance in production-grade HF amplifiers.

Does the MRF1K50H-81MHZ support push–pull amplifier configurations?

Yes, the MRF1K50H-81MHZ explicitly supports push–pull operation due to its dual-gate/dual-drain architecture (Gate A/Gate B, Drain A/Drain B). NXP documentation states "Device can be used single-ended or in a push–pull configuration", and the symmetric pinout and matched thermal characteristics enable balanced harmonic cancellation in narrowband 81 MHz transmitters.

What is the thermal resistance specification for the MRF1K50H-81MHZ, and how is it measured?

The MRF1K50H-81MHZ has a thermal resistance RθJC of 0.10 °C/W, measured under CW conditions: case temperature 78°C, 1500 W CW output, 50 Vdc, IDQ(A+B) = 200 mA, at 88 MHz (Table 2, p.2). This value applies directly to 81.36 MHz operation given the device's wideband thermal behavior and is critical for heatsink sizing in industrial RF systems.

Is the MRF1K50H-81MHZ qualified for high-VSWR environments, and what is the test evidence?

Yes - the MRF1K50H-81MHZ is rigorously tested for high-VSWR resilience. NXP validates >65:1 VSWR tolerance at 230 MHz using 100 µsec pulses at 20% duty cycle with 3 dB overdrive (Table 5, p.5). Though tested at 230 MHz, the device's high avalanche energy absorption capability and lateral MOSFET structure ensure robustness across its full 1.8–500 MHz range, including 81.36 MHz HF applications.

What gate drive voltage range is required for linear operation of the MRF1K50H-81MHZ?

The MRF1K50H-81MHZ requires a gate quiescent voltage VGS(Q) of 1.9–2.9 Vdc (typical 2.4 Vdc) at VDD = 50 Vdc and IDQ(A+B) = 100 mA (Table 4, p.2). For linear Class AB operation at 81.36 MHz, bias must be set within this range using stable, low-noise DC supplies; NXP recommends the MRFE6VS25N driver IC to maintain precise gate control under varying load conditions.