Powering 5G Infrastructure

Aug 20, 2021
Drone circuit board with 5G symbol
As 5G networks expand globally, the number of base stations is increasing rapidly, leading to higher energy consumption. Efficient power solutions are essential to support this growth. This article explores the challenges and presents power module solutions that offer high power density and reliable performance in base station environments.

Table of Contents

Rollout of 5G is now well underway, with coverage on track for one third of the world’s population by 2025, according to the GSMA [1]. Major cell phone manufacturers have launched 5G-enabled phones, which will please those wanting to stream data and videos at up to the theoretical 50Gb/s maximum speed, and worldwide 5G subscriptions are forecast to reach 1.3bn by 2023, according to Statista [2].

However, 5G is much more than faster smartphones – it underpins the technology behind artificial intelligence, cloud computing, autonomous vehicles, the internet of things (IoT), smart cities and industry, and probably more yet-undreamed of applications. As a result, investment in new 5G infrastructure will be high, and network operators will be looking for the quickest possible return on what is projected by Statista to be 1.4 trillion dollars’ telecom services spent in 2021 alone.

5G Frequency Bands and Coverage

5G operates across low, mid, and high-frequency bands. Mid-band frequencies (2.5 – 3.7GHz) are commonly used, offering speeds up to 900Mb/s. High-band frequencies, exceeding 70GHz, provide faster data rates but have limited coverage (~1.5km), making them suitable for dense public areas. Consequently, base stations are categorized into metro, micro, pico, and femto cells, each with varying power outputs and coverage areas. The increased number of base stations is expected to double energy consumption compared to 4G. Therefore, enhancing the efficiency of base station electronics is crucial.

Efficiency Challenges in RF Power Amplifiers

RF power amplifiers (PAs) are integral to base stations but often operate with efficiencies around 60%. Traditionally, Laterally Diffused Metal-Oxide Semiconductor (LDMOS) devices powered from 26-32V DC rails have been used. However, to achieve better efficiency at higher 5G frequencies, Gallium Nitride (GaN) devices, operating at 50-60V, are increasingly adopted, especially in small-cell installations. Improving the efficiency of these PAs is vital to reduce overall energy consumption.

DC/DC Converter Solutions for 5G Base Stations

Reliable and efficient DC/DC converters are essential for powering various components within base stations.

Products from RECOM's RPX and RPL and RPM series

Fig. 2: The RECOM RPX series power module is tiny but rated at up to 4A output

For low-power applications, non-isolated point-of-load (PoL) converters or power modules are used to provide accurate, low-noise voltages directly at the load. RECOM offers ultra-compact, high-efficiency modules utilizing ‘3D Power Packaging®’ technologies.

The RPX series, for example, includes modules like the RPX-1.0 and RPX-1.5 series, featuring a minimal 3 x 5mm footprint in a low-profile QFN package, delivering 1A or 1.5A output, adjustable from 0.8-30V, for input voltages from 4-36V. The RPX-2.5 offers a 2.5A output current with a slightly larger footprint (4 x 4.5mm), and the RPX-4.0 provides 4A output current in a compact 5 x 5.5 x 4.1mm package. These converters integrate inductors and comprehensive protection features, requiring only output voltage setting resistors and input/output capacitors for complete power solutions.
Input VDC vs. Output Current Graph
Fig. 3: Sub-miniature LGA power module ranges available from RECOM
For higher output currents, up to 6A, the RPM series is suitable, with an input voltage range of 4-15V and output adjustable from 0.9-6V. With peak efficiencies up to 99%, the RPM series operates reliably in ambient temperatures up to 90°C without forced air cooling. In space-constrained designs, the RPL-3.0 series is ideal, measuring only 3 x 3 x 1.45mm, with an input voltage range of 4-18VDC and adjustable output voltage between 0.8VDC and 5.2VDC, delivering up to 3A continuous output current. All these modules include comprehensive protection and monitoring features, including shutdown control for energy saving when a 5G base station is in a sleep state.

Conclusion

5G technology promises significant advancements in communication performance, enabling numerous new applications. However, to ensure viability and minimize environmental impact, energy consumption must be minimized. Utilizing reliable power converters with high efficiency and power density, designed for the demanding base station environment, is key to achieving this goal. RECOM supports these applications with a wide range of suitable converters.
Applications
  Series
1 RECOM | RPL-3.0 Series | DC/DC, SMD (pinless), 15W, Single Output
Focus
  • Wide input range (4 - 18V)
  • Low profile 1.45mm
  • Small footprint 3x3mm
  • Adjustable output 0.8 to 5.2V
2 RECOM | RPL-3.0-EVM-1 Series | DC/DC, 15W, Single Output
Focus
  • Evaluation platform for RPL-3.0 Buck Regulator Module
  • Thermal design considerations included
  • EMI Class A filter
  • Easy evaluation of output voltage selection, control, power good and sensing functions
3 RECOM | RPM-6.0 Series | DC/DC, SMD (pinless), Single Output
Focus
  • High power density (L*W*H = 12.19*12.19*3.75)
  • Wide operating temperature -40°C to +90°C at full load
  • Efficiency up to 99%, no need for heatsinks
  • 6-sided shielding
4 RECOM | RPX-1.0 Series | DC/DC, SMD (pinless), 5W, Single Output
Focus
  • Buck regulator power module with integrated shielded inductor
  • 36VDC input voltage, 1A output current
  • SCP, OCP, OTP, and UVLO protection
  • 3.0 x 5.0mm low profile QFN package
5 RECOM | RPX-1.5 Series | DC/DC, SMD (pinless), 7.5W, Single Output
Focus
  • Buck regulator power module with integrated shielded inductor
  • 36VDC input voltage, 1.5A output current
  • SCP, OCP, OTP, and UVLO protection
  • 3.0 x 5.0mm low profile QFN package
6 RECOM | RPX-2.5 Series | DC/DC, SMD (pinless), 12.5W, Single Output
Focus
  • Buck regulator power module with integrated shielded inductor
  • 28V maximum input voltage
  • 2.5A maximum output current
  • SCP, OCP, OTP, OVP and UVLO protection
7 RECOM | RPX-4.0 Series | DC/DC, SMD (pinless), 20W, Single Output
Focus
  • Buck regulator power module with integrated shielded inductor
  • 36VDC input voltage, 4A output current
  • Programmable output voltage: 1 to 7V
  • Ultra-high power density: 5.0 x 5.5mm QFN footprint
8 RECOM | RPX-4.0-EVM-1 Series | DC/DC, 20W, Single Output
Focus
  • Evaluation platform for RPX-4.0 buck regulator module
  • Thermal design considerations included
  • EMI class B filter
  • Easy evaluation of output voltage selection, control, and sensing functions
9 RECOM | RPM-6.0-EVM-1 Series | DC/DC, Single Output
  • Evaluation platform for RPM-6.0 buck regulator modules
  • Thermal design considerations included
  • EMI Class B filter
  • Easy evaluation of trimming, sequencing, soft start, enable and sensing functions
10 RECOM | RPX-1.0-EVM-1 Series | DC/DC, 5W, Single Output
  • Evaluation platform for RPX-1.0 buck regulator module
  • Thermal design considerations included
  • EMI class B filter
  • Easy evaluation of output voltage selection, control, and sensing functions
11 RECOM | RPX-1.5-EVM-1 Series | DC/DC, 7.5W, Single Output
  • Evaluation platform for RPX-1.5 buck regulator module
  • Thermal design considerations included
  • EMI class B filter
  • Easy evaluation of output voltage selection, control, and sensing functions
12 RECOM | RPX-2.5-EVM-1 Series | DC/DC, 12.5W, Single Output
  • Evaluation platform for RPX-2.5 buck regulator module
  • Thermal design considerations included
  • EMI Class B filter
  • Easy evaluation of output voltage selection, control and sensing functions