Digital DC/DC converter in half-brick package for Radio Frequency Power Amplifiers

Flex Power Modules announces the BMR685, the first digital DC/DC converter for Radio Frequency (RF) Power Amplifiers in the half-brick form factor that can provide continuous output power of up to 1300 W.

With telecoms infrastructure shifting to 5G, the RFPA is becoming increasingly power-hungry, and RF Power Amplifier designers are moving from LDMOS to Gallium Nitride (GaN) Transistors. Overall, there’s a demand for highly efficient DC/DC converters, that can deliver the power required in a compact package. The BMR685’s power-handling capabilities make it well-suited to these high-power RF Power Amplifier applications, for both LDMOS and GAN needing a 50 V rail.

The new converter provides high efficiency of up to 97.2% at half load. It has an output voltage range of 25 V to 55 V, and can deliver up to 26 A output current. Its input voltage range is 36 V to 75 V, and isolation between input and output is 2250 V.

The BMR685 includes digital functionality, accessed over a PMBus interface, which enables easy monitoring of temperature, voltage and current, as well as simple adjustment of output voltage. It is supported by the Flex Power Designer software tool.

The converter has an operating temperature range of -40 °C to +125 °C, with 100% available power at 100 °C baseplate temperature. It includes comprehensive over-voltage, over-temperature and short-circuit protection mechanisms, which means it achieves a long operational lifespan, with a mean time between failures (MTBF) of over 4.97 million hours.

David Xie, Director R& D and Product Management, Flex Power Modules, said: “RF Power Amplifier applications are demanding more and more power, without compromising on efficiency and features. The BMR685 meets all these requirements and more, in a compact package that is easy to integrate into Power Amplifier designs.”

Provided in the industry-standard half-brick format, the BMR685 measures 61.0 x 57.9 x 12.7 mm (2.4 x 2.28 x 0.5 in). It meets safety requirements according to IEC/EN/UL 62368-1.

Flex Power Modules’ entire RF Power Amplifier portfolio including the new BMR685 will be presented at the Electronica China event, taking place in Shanghai between 14 – 16 April 2021.

The BMR685 will be available in Q2 2021, and samples are available now.