How MRAM fuels smart city development

Smart cities are popping up all over the world. One of the key challenges in deployment is the critical mass of interconnected devices with end-point processing that increasingly needs local storage of data and software. Magnetoresistive random-access memory (MRAM) promises to significantly improve electronic products by storing greater amounts of data, enabling faster data access and consuming less energy than existing electronic memory.

While smart cities are at different stages of development, among the most advanced are Barcelona, Spain; Columbus, Ohio; Dubai and Hong Kong. The governments of all these cities recognize the benefits that can be gained for their citizens by leveraging information and communication technology (ICT).

Smart cities are defined as such because they implement ICT to “create, deploy and promote development practices to address urban challenges and create a joined-up technologically-enabled and sustainable infrastructure,” according to TWI Ltd.

While the concept of smart cities has existed since the mid-1960s, it wasn’t until internet of things (IoT) technologies – such as sensors, edge node devices and advanced memory technologies – were developed that we could achieve the level of “smart” that we see today. Smart city deployment drives the need for more intelligence throughout a city infrastructure. IoT-connected devices make it possible to optimize energy utilities, traffic management and safety measures.

Data storage challenges

One of the key challenges for smart city deployment over the years was the ability to achieve a critical mass of interconnected devices to gather, process, store and share the volumes of data needed to keep a city humming. Devices such as smart meters, renewable energy systems and smart cameras all now have a degree of end-point processing that increasingly needs local storage of data and software.

For example, residential and commercial “smart meters” record energy consumption data from electric and other utilities every minute of the day. The data is transmitted back through the infrastructure to allow for time-of-use billing, enable outage reporting and diagnosis and facilitate sales of micro-generated energy, such as solar panel or wind turbine sources. These meters need memory that can record data quickly without concern for wearing out.

High-bandwidth 5G is another technology that is critical to smart city deployment. For example, autonomous transportation systems rely on 5G to provide device-to-device connectivity. This trend, coupled with the move to edge-based processing, has also created the need for more responsive and intuitive memory systems that can capture critical information coming from the connected systems.

Sensor networks are deployed in smart cities to retrieve and record information that systems use to interpret, optimize and respond in a continuous manner. Recent advances in memory density, write cycle endurance and bandwidth are now giving system designers the ability to capture and process data from the far edge of the network through to the cloud.

Solar panels as renewable energy sources are critical to today’s smart city infrastructure. However, converting sunlight to energy through photovoltaics requires a significant amount of electric signal conversion and conditioning to maximize the amount of energy harvested under varying conditions. Once again, access to local, highly reliable memory technology is critical for monitoring and optimizing solar inverter processes to ensure ongoing and continuous use.

MRAM addresses challenges

EMxxLX STT-MRAM (Source: Everspin)

MRAM is a method of storing data bits using magnetic states instead of the electrical charges used by devices such as dynamic random-access memory (DRAM). It requires no power to retain stored memory. The polarization of the magnetic domain causes a change in resistance that determines the zero and one values of the data stored, and any stored information is always available. By combining the high speed of static random-access memory (SRAM) and the non-volatility of Flash, MRAM can store two to four times the amount data of NOR Flash memory on a single chip,  while consuming 100 times less energy to write the data to the memory. The reduction in energy comes from the speed of the writes, which is at least 100 times faster than Flash.

MRAM has emerged as an extremely flexible memory that offers RAM-like performance but with data persistence, giving designers confidence that their information is going to be protected in cases where power loss or harsh environments are present. This makes MRAM an ideal solution for all the aforementioned smart city applications.

MRAM has been in production at Everspin for more than 15 years. Advancements in density and speed have made it another viable, highly reliable memory choice. Together with traditional DRAM and NAND, MRAM can help solve the data storage challenges of smart city deployments around the world.