Smart Power Meters & Energy Subsystems – FeRAM in Use

Challenges in the Smart Grid Segment

In modern smart grid applications such as smart meters and energy subsystems, reliability and longevity are paramount. Devices in this area – from 3-phase electricity meters to decentralized sensor systems – often have to be able to operate for over 10 years without maintenance. At the same time, measurement data (e.g., consumption values, mains voltages, events) is continuously generated and must be stored in real time. A particular challenge is to keep this data safe even in the event of power failures or voltage dips. This is the only way to ensure that consumption bills remain accurate and complete. In addition, attempts at manipulation – such as opening the housing or using strong magnets – must be detected and logged immediately.

Typical Technical Problems with Conventional Storage Devices

Most conventional non-volatile memory (EEPROM, flash) only partially meets the above requirements. A key problem is the limited number of write cycles allowed. In a smart meter that logs new consumption data every minute or even every second, this limit can be reached quickly. Developers must therefore either work with complex wear leveling or limit the write frequency – neither of which is ideal.

Added to this is the comparatively low write speed: write operations often take several milliseconds and are performed page by page rather than byte by byte. In real-time applications, this can lead to data loss if the memory does not write fast enough or if a power failure occurs before the operation is completed.

Another problem is the high energy consumption during writing. EEPROMs and flash often require internal charge pumps with corresponding power consumption. This is critical in devices with backup capacitors or battery power supply – for example, for "last gasp" in the event of a power failure. Finally, battery-buffered SRAMs require regular maintenance, which rules out maintenance-free systems in the long term.

FeRAM from RAMXEED as a Solution

FeRAM (ferroelectric RAM) combines the speed of RAM with the non-volatility of EEPROM and flash. The memory modules from RAMXEED (formerly Fujitsu Semiconductor) offer several technical advantages that make them ideal for use in energy measurement systems:

• Very fast write operations: Data is written with virtually no delay – ideal for real-time logging and for saving the last values in the event of a power failure. Byte-by-byte writing without first deleting entire blocks simplifies data handling.
• High write cycle endurance: FeRAM can be written over many billions to trillions of cycles – a clear advantage over EEPROM or flash. Even with data storage every second over many years, no wear is to be expected.
• Low energy consumption: Writing processes require very little power, as no charge pumps or erase cycles are necessary. This conserves batteries or capacitors in emergency mode and reduces energy consumption in continuous operation.
• Reliable data retention: Written data is retained even in the event of a complete power failure. FeRAM is non-volatile and temperature-stable – a key advantage for outdoor devices or applications with sporadic power supply.
• Robust against environmental influences: FeRAM is insensitive to magnetic fields and electromagnetic interference, such as those that can occur in transformer stations. Even targeted manipulation attempts with magnets cannot influence the memory content.

RAMXEED offers a broad portfolio of FeRAM devices with SPI or I²C interfaces in capacities ranging from a few kilobits to several megabits – many of which are pin-compatible with EEPROMs. In many cases, existing designs can therefore be upgraded without hardware changes. Automotive-qualified variants with an extended temperature range are also available for safety-critical or industrial applications.

Typical Areas of Application

In addition to smart meters and energy modules, FeRAM is also suitable for other industrial applications where frequent data access must be combined with secure storage:

• Industrial controllers (PLC): Here, FeRAM can securely store states, configurations, or error logs even in the event of a power failure – without a battery.
• Emergency systems and loggers: In safety-critical devices (e.g., airbag control units, UPS), the last operating states can be saved without delay.
• Medical technology and sensor technology: Energy-autonomous devices benefit from low energy consumption and high reliability in data storage.

FeRAM is therefore useful wherever high write loads, energy efficiency, and data security are required – even if the capacity is lower than that of flash memory.

Memorysolution's Role in Selection and Implementation

The selection of the right memory module depends heavily on the specific application. As a consulting distributor, Memorysolution supports developers, system integrators, and OEMs in the successful integration of FeRAM—both technically and logistically:

• Expert selection advice: Interface, capacity, temperature suitability, or certification—Memorysolution helps you select the optimal RAMXEED component.
• Design-in support: Memorysolution provides technical expertise, samples, reference designs, and application notes to support integration into existing circuits or software designs.
• Long-term supply: Ensuring delivery capability is crucial, especially for long-life devices. Memorysolution takes care of forecast management, EOL monitoring, and stocking – reliably throughout the entire product life cycle.

Through this close partnership with RAMXEED and technical support in the design-in process, Memorysolution lays the foundation for long-lasting, maintenance-free devices based on modern FeRAM technology.

Conclusion: Technical and Economic Added Value

FeRAM offers significant advantages over conventional memory in energy- and data-critical applications such as smart power meters: High write cycle endurance, low energy consumption, and reliable data security even in the event of a power failure make FeRAM the ideal solution for long-lasting embedded systems. RAMXEED provides the right technology with its specialized FeRAM portfolio, while Memorysolution supports developers in selection and implementation with technical expertise and reliable distribution. The result is a future-proof memory solution that not only impresses with its technology, but also offers long-term economic advantages.