Cellular communications have come a long way since the introduction of analog cellular networks in the early 1980s. Today, as the market migrates from 4G to 5G network solutions, the cellular communications industry is laying the groundwork for faster data speeds, lower latency, and huge leaps in capacity, user density, and reliability. For example, 5G can not only increase data rates ( 100x ) and network capacity (10x), but also dramatically reduce latency to below 1 ms1 and simultaneously enable near-ubiquitous connectivity for billions of connected devices is part of the growing Internet of Things (IoT). A typical 5G beamforming transmitter consists of digital MIMO, data converters, signal processing components, amplifiers, and antennas, as shown in Figure 12.
Powering FPGAs To fully realize the benefits of 5G, designers need to use higher frequency radios by incorporating more integrated microwave/millimeter wave transceivers, field programmable gate arrays (FPGAs), higher rate data converters, and High-power, low-noise power amplifiers (PAs) suitable for smaller cells can take full advantage of the new spectrum to meet future data capacity needs. In addition, these 5G cells will also contain more integrated antennas to apply massive multiple-input, multiple-output (MIMO) technology for reliable connectivity. Therefore, a variety of state-of-the-art power supplies are required to power 5G base station components.

Modern FPGAs and processors are fabricated on advanced nanoscale processes because they typically perform fast computations at low voltages (<0.9 V) at high currents in compact packages. In addition, newer generations of FPGAs require lower core voltages to dramatically increase computing speed, while at the same time requiring higher I/O interface voltages and additional DDR memory supply rails. 3,4,5 Therefore, a single FPGA actually requires multiple voltages and different current ratings with tight tolerances for optimal operation. More importantly, to avoid damage, the timing of these voltage rails must be controlled in the correct order. Power supplies built using the latest semiconductor technology combined with leading circuit topologies and advanced packaging techniques can meet these stringent requirements. However, if a designer fails to use the proper power management solution properly, it can lead to a variety of risks, from inefficiency to thermal performance and other undesirable performance-related issues.

Low Noise Power Supply for High Speed Data Converters

Likewise, faster-running precision data converters such as analog-to-digital converters (ADCs) and digital-to-analog converters (DACs) require multiple power rails, such as 1.3 V, 2.5 V with very low noise and DC ripple V and 3.3 V. 6 Typically, these high-speed ADCs and DACs are placed on crowded printed circuit boards (PCBs) with limited space available. Therefore, the power supply sensitivity of ADCs and DACs must be a primary consideration when designing power systems for these high-speed data converters.

Figure 1. High-level high-level functional block diagram of a beamforming transmitter in a 5G system

By combining the advantages of advanced semiconductor and packaging technologies, ADI's µModule® Silent Switcher® regulators can easily solve this problem, meeting the efficiency, density and noise performance needs of high-speed data converters. A good example is the Silent Switcher LTM8065, which can provide a lower noise, more compact, and more efficient powering solution for these devices. Unlike traditional discrete solutions, the LTM8065 can significantly reduce component count and power board space without sacrificing data converter dynamic performance. The device integrates the switch controller, power switch, inductor, and all supporting components in a single RoHS-compliant BGA package.

In some cases, to maximize power supply rejection ratio (PSRR) performance, a linear regulator can be used in the power path after the switching regulator. The ADP7118 is one such low dropout (LDO), low noise linear regulator that handles a wide input voltage range with high output accuracy, low noise, high PSRR, and excellent line and load transient response. And there are many more models in this product family, which can be properly selected using software tools such as ADI's LTpowerCAD and LTspice®.

Power Management for PAs and Transceivers

These next-generation radios combine integrated transceivers and low-noise, high-power microwave/millimeter-wave PAs with wider bandwidths, and their digital control and management systems require the use of multiple specialized power technologies. For example, gallium nitride (GaN)-based low-noise, high-power PAs will require voltages as high as 28 V to 50 V, while FPGA-based control and high-speed ADCs and DACs will require multiple lower voltages with appropriate Sequence control, monitoring and protection functions. 7,8 State-of-the-art DC/DC converters provide the efficiency (>90%), power density, low noise performance and control capabilities required by these 5G PAs.

Under the enormous pressure that the new generation (5G) products must outperform the previous generation (4G), there is little room for compromise. Therefore, ADI, as a company that focuses on all aspects of the base station RF chain and has a comprehensive knowledge of the power management tools needed to power these applications, is able to provide the right power solutions for today's 5G PAs and transceivers. ADI offers the industry's broadest portfolio of high-performance Power by Linear 8482 ; products ranging from high-efficiency, high-density DC/DC converter modules to power management ICs (PMICs) and ultra-low noise linear regulators including power sequencing, monitoring and protection features), which can provide a more comprehensive approach to powering the 5G signal chain.

ADI's µModule regulator and Silent Switcher technology is a complete power system-in-package solution capable of delivering precise voltages with highest efficiency (>95%) and high power density in a tiny package with high reliability and lowest EMI with noise. These solutions are designed to power high-performance RF systems with the highest power conversion efficiency and density without adding noise or interference to the radio signal of interest, ensuring optimum performance of these RF PAs and other such RF circuits .

Likewise, to address the challenges of power supply sequencing when multiple supply rails are required in a circuit, ADI offers a family of sequencers ranging from two supplies (ADM6819/ADM6820) to 17 channels (ADM1266). Monitoring device voltage, current, or temperature is critical to ensure that the system operates properly, efficiently, and safely. To this end, ADI offers devices such as the LTC2990.

Summarize

In summary, ADI's Power by Linear portfolio includes low noise LDO regulators, low EMI and highly integrated multirail DC/DC converter µModule devices, Silent Switcher technology, and other power management ICs including power sequencers, supervisors and protection circuits), all of which give ADI the ability to offer the broadest portfolio of power supplies in the industry. This series fully meets the power needs of 5G base station components, including software design and simulation tools such as LTpowerCAD and LTspice. These tools simplify the task of selecting the right power management solution for the device, thus providing the best power solution for 5G base station components.