Meeting Power Demands of Modern Microprocessors

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There are many demands for increased computing power in the modern world. The explosion in the volume of data created, processed, and stored has been driven by the rapid expansion of artificial intelligence (AI). AI has impacted every aspect of modern life, from the cars we drive to how we shop. In the industrial world, edge computing has revolutionized manufacturing, creating a more flexible factory space that can respond quickly to changing needs. All these applications require greater computing power, which leads to a need for more capable, high-performance processors.

The modern processor has evolved enormously to cope with this increased demand. Modern processors now boast process technology nodes as small as 3nm, and while design voltage requirements have dropped from 5V to as low as 0.8V, the smaller node size demands greater voltage precision to ensure optimum performance. The smaller node size has also enabled a significant increase in transistor density, which, in turn, raises heat density. This makes power efficiency even more critical to reduce power dissipation and ensure reliable operation.

The faster speeds of modern processors allow for quicker responses. While this speed allows them to work on new tasks rapidly, their performance demands a similar response speed from their power supply. If the power supply cannot react at the same speed, voltage drops at critical moments can cause system crashes or even damage to hardware.

In addition to these requirements comes the need for efficiency. While energy prices have risen worldwide, the energy demands of data centers have been driven further by power-hungry AI processors. Inefficiencies in power supplies result in increased thermal loads that must be managed. This combination of factors has changed the way in which energy is delivered.

In this blog, we’ll review some of the challenges engineers face when dealing with modern power delivery and examine how NXP’s Power Management Integrated Circuits (PMICs) provide scalable, efficient, and reliable solutions for next-generation processors.

The Persistent Problems of Power

The traditional power delivery method to the printed circuit board (PCB) is unsuitable for modern computing devices. Early microprocessors required far less complicated power supplies, as single-core processors required one voltage level, known as single-rail power supplies. This power was converted from mains power to direct current at relatively high voltages, originally 5V, but it decreased as processors became more sophisticated and nodes became smaller. 

However, the multiple cores in modern processors operate at unique voltages and clock speeds. These multi-core processors, therefore, require systems that can provide the correct voltage for each function—a process known as multi-rail power management. Each rail provides power to different blocks within the processor, including memory, core, and I/O functions. Multi-rail power systems are designed to deliver specific voltage and current to each core as required.

Changes in how we power processors reflect our new relationship with energy. We are encouraged to create more energy from renewable sources to help combat climate change. Operators are investing heavily in the opportunity to use technologies such as solar cells to reduce the cost of the energy they consume. In this method, the electricity is stored in an energy storage system (ESS) consisting of a large bank of batteries. In contrast to traditional grid-supplied power, the output of the ESS is direct current. There is, therefore, a need for power management systems that can deliver the correct voltage from a DC power supply.

At the same time, there is considerable interest in using new techniques to increase the efficiency of power supplies. Driven in part by the move within the automotive industry to use 48V power supplies, this new approach to power created the opportunity to increase efficiency. One major contributor to power loss in power delivery networks is resistive conduction loss, which decreases efficiency in proportion to the square of the current (P = I²R~1/Efficiency). Increasing voltage and reducing the current delivers the same amount of power but significantly improves the overall efficiency of the system.

Every step-down in voltage impacts efficiency. Converting from 48V to 5V and then again to even lower voltages will introduce losses within the power system. A multi-rail power supply that can deliver a range of different voltages as required by the cores of the processor without the need for multiple conversion steps will improve overall efficiency and reduce the waste associated with fixed-voltage systems.

Power in Challenging Applications

To compound the challenges of these high-performance systems, the emergence of embedded systems and edge AI has seen more powerful processors finding their way out of the data center and into everyday situations. Therefore, the power systems that support them must conform to stringent safety standards. In the automotive world, the rise of self-driving vehicles with advanced driver assistance systems (ADAS) has focused on the need for safety in electronic systems, while Automotive Safety Integrity Level (ASIL) compliance ensures the safety of road users. By classifying the dangers posed by failure in safety-critical situations, ASIL compliance allows designers to choose the right components for demanding applications.

Faced with these performance and safety challenges, designers need a single solution that can deliver power for the complex needs of the modern microprocessor. By optimizing power efficiency and simplifying supply sequencing for application processors, PMICs from NXP Semiconductors are the dedicated solution for delivering power within even the most complex computing device.

NXP’s PMICs integrate multi-rail power into a single component, resulting in easier PCB designs while easing supply challenges by reducing the number of components required. They are designed to provide dynamic voltage scaling (DVS), allowing the PMIC to deliver energy as needed, resulting in reduced energy waste and improved efficiency. In addition, this improvement in efficiency also reduces the amount of heat created, which helps to minimize the associated cost and complexity of thermal management.

Built-in compliance with both ASIL-B and -D ensures that NXP PMICs are ideal for the next generation of automotive designs. To meet the long-term demands of automotive, industrial, and IoT applications, NXP’s Product Longevity Program guarantees product availability for a minimum of 10 or 15 years, depending on the device. This ensures design continuity and supply chain stability over time.

The Future of Power Management

Computing systems continue to evolve, with smaller node sizes and greater capabilities, placing new demands on the power systems that supply them. The introduction of AI systems into everyday applications and new developments in the automotive and industrial worlds mean that traditional power architectures are no longer sufficient.

As the role of PMICs grows increasingly important, NXP offers a range of solutions that deliver precise, multi-rail, and scalable power supplies with built-in safety compliance. With its PF81, FS65, and PF0100 PMICs, NXP helps designers reduce complexity, increase efficiency, and deliver more sustainable products for the future of high-performance computing devices.

David Pike is well known across the interconnect industry for his passion and general geekiness. His online name is Connector Geek.