MRF173

Overview

The MRF173 is an N-channel enhancement mode RF MOSFET designed for VHF power amplifier applications. It delivers 80 W output power at 150 MHz with a typical gain of 13 dB and minimum efficiency of 55% when operated at 28 V. The device supports frequencies up to 175 MHz and features low thermal resistance, ruggedness testing at rated power, nitride passivation for reliability, and excellent thermal stability suitable for Class A operation.

Feature Summary

• Enhancement mode N-channel architecture with vertical planar structure
• Nitride passivated die for enhanced reliability
• Excellent thermal stability suited for Class A operation
• Immunity from thermal runaway and load mismatch damage

Applications

• Broadband commercial and military solid state transmitters
• FM broadcast power amplifiers
• TV channel frequency band amplifiers

Procurement Notes

Verify the specific package style against the datasheet before ordering. Confirm that the application environment meets the thermal requirements for the selected mounting method. Ensure gate bias circuits are designed to handle the DC open circuit nature of the gate terminal properly.

Selection Notes

Select this component for high-power VHF applications requiring broadband performance. Consider the simple bias system requirements and the ability to control power output via DC gate voltage. Evaluate impedance matching networks using provided small-signal scattering parameters for initial design approximations.

Part Context

This part belongs to MACOM's RF MOSFET line, characterized by high gain and low noise figures. It utilizes a planar design to avoid processing difficulties associated with V-groove power FETs. The device is optimized for linear amplification and modulation systems due to its wide-range power control capabilities.

Replacement Considerations

Consult MACOM documentation for direct substitutes. Verify pinout compatibility and thermal characteristics if considering alternative manufacturers' devices for existing designs.

FAQ

How is the power output controlled?

Power output can be varied from the rated value down to zero by adjusting the DC gate voltage, facilitating manual gain control and modulation.

What is the recommended quiescent drain current?

The device was characterized at IDQ = 50 mA, which is suggested as the minimum value, though it may need optimization for special linear amplification applications.

Does the gate draw current?

No, the gate is a DC open circuit and draws no current, allowing for simple resistive divider bias networks.