The NXP Semiconductors MRF13750HR5 is a high-power RF LDMOS transistor designed for operation in the VHF and UHF frequency ranges, optimized for commercial, industrial, and military RF amplifier applications. It offers high output power, excellent gain, and linearity, making it suitable for broadband linear amplification, base station transmitters, and high-efficiency RF power stages. The device integrates advanced LDMOS technology, delivering robust performance under high-voltage and high-temperature conditions while maintaining low distortion and high reliability. Its low thermal resistance and rugged design support continuous high-power operation in demanding RF environments.

## Functional Overview

The MRF13750HR5 is a laterally-diffused MOSFET optimized for high-efficiency RF power amplification. The device features a grounded-source configuration with internally matched input and output impedances, facilitating integration into amplifier circuits with minimal external matching components. It is capable of both linear and saturated operation, supporting applications requiring high output power, low intermodulation distortion, and efficient use of supply voltage. The transistor includes a thermally optimized package to support effective heat dissipation and reduce the risk of thermal runaway, enabling reliable operation at high output power levels.

## Key Specifications

* Frequency Range: 1.0 MHz to 400 MHz, supporting broadband VHF and UHF RF applications.
* Output Power: 150 W typical in linear operation at 28 V supply, suitable for high-power RF amplification.
* Drain-Source Voltage (Vds): 50 V maximum, allowing robust operation with standard RF power supply rails.
* Quiescent Drain Current (Idq): 500 mA typical at Vds = 28 V, optimized for linearity in Class AB operation.
* Gain: 15 dB typical at 28 V, providing high power gain for RF amplifier stages.
* Input Impedance: 50 Ω nominal, simplifying interface with standard RF sources and preamplifiers.
* Output Impedance: 50 Ω nominal, supporting direct connection to 50 Ω transmission lines and loads.
* Drain Efficiency: Up to 65% in linear operation, depending on load matching and frequency.
* Thermal Resistance: 0.75°C/W junction-to-case, supporting high-power operation with proper heatsinking.
* Package: Hermetically sealed RF ceramic-metal package with flange for heat sinking, ensuring robust thermal and mechanical stability.
* Operating Temperature Range: -55°C to +150°C junction temperature, supporting industrial and military applications.
* Biasing: Designed for Class AB operation with external gate bias adjustment for optimal linearity and efficiency.

## RF Performance and Linearity

The MRF13750HR5 is optimized for high linearity in RF amplification, minimizing intermodulation distortion in multi-carrier signals. Its LDMOS structure provides low on-resistance and low capacitance, allowing efficient high-frequency operation and fast switching. The device supports broadband operation across the VHF and UHF spectrum, making it suitable for linear amplifiers in radio transmitters, commercial broadcast, and point-to-point communication systems. The transistor exhibits stable gain and output power over the full frequency range, with low thermal drift and predictable behavior under varying load conditions.

## Thermal Management and Packaging

The device features a thermally efficient package with a flange for attachment to a heatsink, ensuring minimal junction temperature rise during continuous high-power operation. The package’s hermetic sealing protects against moisture, corrosion, and environmental stress, enhancing reliability in outdoor and industrial deployments. Proper thermal design, including heatsink selection and airflow management, is essential to maintain junction temperatures below the maximum rating and prevent long-term performance degradation.

## Gate Bias and Drive Requirements

The MRF13750HR5 requires a properly configured gate bias to ensure Class AB operation with high linearity and efficiency. Gate voltage and current must be carefully controlled to prevent overdrive, reduce quiescent power dissipation, and maintain consistent RF performance. The transistor is compatible with standard low-impedance RF drive circuits, with input matching networks recommended to optimize gain and minimize reflection. External bias networks and thermal monitoring are recommended for applications with high duty cycle or continuous-wave operation.

## Applications

The MRF13750HR5 is suitable for a range of high-power RF applications, including:

* Linear RF power amplifiers for commercial and military VHF/UHF transmitters.
* Base station transmitters for land mobile radio and broadband communications.
* Industrial RF heating and plasma generation systems.
* Amateur radio high-power linear amplifiers.
* Broadcast transmitters requiring high linearity and robust thermal performance.

## Reliability and Protection

The LDMOS structure of the MRF13750HR5 provides inherent robustness against thermal and electrical stress. The transistor can handle high peak currents and load mismatches with minimal degradation. Hermetic packaging and thermally optimized design minimize environmental stress effects, while proper biasing prevents overstress of the gate and drain. Applications requiring pulsed or continuous high-power operation should implement appropriate thermal management, overcurrent protection, and load monitoring to ensure long-term reliability.

## Design Considerations

Designers integrating the MRF13750HR5 should focus on thermal design, bias network optimization, and RF matching to achieve maximum efficiency and linearity. Input and output networks should maintain 50 Ω impedance over the operating bandwidth, minimizing reflections and losses. Proper gate drive impedance, decoupling, and thermal monitoring are essential for high-reliability applications. The device supports parallel operation for higher output power, but care must be taken to balance currents and maintain stable thermal performance across all devices.

## Summary

The NXP Semiconductors MRF13750HR5 is a high-power, broadband LDMOS RF transistor designed for linear and efficient amplification in VHF and UHF applications. With 150 W output power, 50 V drain voltage capability, low on-resistance, and high linearity, it is suitable for demanding commercial, industrial, and military RF amplifier applications. Its thermally efficient, hermetically sealed package and robust LDMOS structure ensure reliable operation under high-power and high-temperature conditions. The device provides system designers with a high-performance, high-efficiency solution for broadband RF power amplification, linear transmitters, and industrial RF systems.