EuMW 2018: 65V LDMOS transistor opens up RF power options

With more power density, a lower current level and wider safety margins than previous RF power solutions, 65V LDMOS enables more integrated, highly reliable Industry 4.0 systems that can now leverage the superior level of control that solid state technology enables, combined with a high degree of energy management.

The MRFX series of 65 V LDMOS devices targets industrial, scientific and medical (ISM) applications such as laser generation, plasma processing, magnetic-resonance imaging, skin treatment and diathermy, as well as the growing segment of RF Energy where transistors replace vacuum tubes in industrial heating machines.

They are also designed for radio and TV broadcast transmitters.

“In less than a year, more than 100 customers have already adopted NXP’s 65V LDMOS,” said Pierre Piel, senior director and general manager for multi-market RF power at NXP. “Beyond the performance leadership, it is the unprecedented availability of enabling tools that explains this success. Namely, NXP’s power blocks with easy to reproduce designs and available system and software enablement. That means simplified RF design and fast time to market, so our customers can focus on the core value of their products.”

65 V LDMOS made its debut in 2017 with the MRFX1K80H device, capable of 1800W CW (continuous wave) in an air-cavity ceramic package.

Many new reference circuits for the MRFX1K80H have since been designed, enabling RF designers to jump-start their development at 27, 64, 81.36, 87.5-108, 128, 175, 174-230 and 230 megahertz (MHz).

Focusing on ease of use to enable faster development time and design reuse from previous 50 V solutions, NXP recently added to its 65V offering:

• MRFX1K80N: 1800W over-moulded plastic package version of the MRFX1K80H device, enabling a 30% lower thermal resistance (0.06 °C / W).
• MRFX600H: 600W solution in a small footprint, featuring an unmatched 12.5-ohm output impedance to fit a 4:1 output transformer.
• MRFX035H: 35W driver of previous final-stage devices. It comes with an unmatched 50-ohm output impedance, for the most compact board layouts.

Power supply manufacturers are enabling 65V solutions. ABB Embedded Power is developing a 3.5kilowatt (kW), 65V power supply unit to drive NXP transistors of the MRFX Series. “Our collaboration with NXP will make possible a new generation of robust RF systems that enable higher power applications reliably delivering high efficiency, flexibility, and control for faster development time,” said Jim Montgomery, Sr. Product Manager.