Flex Power Modules is working with OpenRAN, and O-RAN Alliance to broaden its range of isolated DC/DC converters for RFPA.

The IEEE, says Flex Power, is stating that existing LTE RFPA solutions are not suitable for operation in the 5G range due to frequency incompatibility and, therefore, will not achieve high efficiency if use continues.

To overcome the challenges of creating RFPAs that are able to balance higher power with greater efficiency, designers can exploit the benefits of DC/DC conversion technologies.

The company offers the PKM-D series of fully regulated analogue DC/DC converters, the most recent additions to which are the PKM4516AD and PKM4516HD.

Both are supplied in industry standard quarter-brick format, with output up to 18A/504W using the 28 V nominal PKM4516AD, and up to 10A/500W with the 50 V nominal PKM4516HD. Crucially, both deliver high efficiency: 95.5% at 28Vout half load with the PKM4516AD, and 95.1% at 50Vout half load using the PKM4516HD.

Providing high MTBF (mean time between failures) of just under 8 million hours, another key feature is the output voltage adjust function of up to +20%/-50%, which makes it possible to power a wide range of power transistors, and support linearity and efficiency optimization.

Power-saving factors are important as predictions estimate that 5G data rates could reach 107 exabytes (EB) per month by 2023.

Around 5kWh is currently required to support every GB of internet data, so 5G power consumption will need to reduce significantly if it wants to be environmentally sustainable and economically viable.

To help further in this regard, designers of power-hungry RFPAs are increasingly moving from LDMOS to gallium nitride (GaN) transistors, initially at base station level, due to their inherent high breakdown voltage, high power density, large bandwidth and higher efficiency.

Flex Power also offers the PKJ4000 series of DC/DC converters in half-brick format, which target even higher power RFPA applications.

This series delivers 28 or 50VDC at up to 700W of power from an input voltage range of 36 to 75V. In addition, the company is finding that the eighth brick PKB-D series is proving popular as a supporting product since 5V is often needed in varying power levels alongside the 50V (mostly for GaN) or 30V (mostly for LDMOS).

Products in development include a range of digital isolated DC/DC converters for RFPAs that will extend the benefits to include monitoring, configuration and control through the PMBus open protocol.