Monday, June 20, 2022
Power is precious in space, which makes ferroelectric RAM (FRAM) an ideal memory for off–planet applications. It’s not just the energy consumption during operations that matters, but also when a device is programed— which is a key feature of Infineon Technologies’ latest serial interface (FRAM) for extreme environments.
Aside from power considerations, exposure to radiation is another key consideration for memory devices going into space. Infineon claims its QML–V qualified FRAM is the space industry’s first radiation–hardened (rad–hard) FRAM.
In an interview with EE Times, Helmut Puchner, vice president fellow of Aerospace and Defense at Infineon Technologies, said the company’s latest rad–hard FRAM devices have superior write capabilities with lower power requirements than alternatives for space applications, including non–volatile EEPROM and serial NOR Flash devices. The new FRAM also supports system designs with fewer components, improved performance, and no compromise in reliability, he said.
The 2 megabyte density device with Serial Peripheral Interface (SPI) has near–infinite endurance with no wear leveling and over 100–year data retention available to space applications. The device also boasts 10 trillion read/write cycles and 120 years data retention at 85°C, with an operating voltage range of 2.0 V to 3.6 V, according to Puchner. The lowest operating current is 10 mA maximum, with an extreme low programming voltage of 2V.
“In some of the satellite payloads, especially scientific ones, they do a lot of calibration,” Puchner said. Instrumentation that needs to be calibrated has specific power budgets during programming, not just operations, he added.
The data retention characteristics of FRAM are also appealing for space–based applications, and include data logging of mission critical data, telemetry storage, and command and control calibration data storage.
“A lifetime of a satellite could be 25 years,” Puchner explained, so a memory device needs to be able to be updated often without extensive wear or power consumption. Other uses for the new Infineon FRAM include boot code storage solutions for microcontrollers, FPGAs, and ASICs. He said support for the industry standard SPI protocol improves ease–of–use and supports a smaller footprint and lower pin count, and serial protocols are increasingly used in satellite and space applications.
Even though the market for space–bound memory is growing with more commercial flight launches, Puchner noted it’s still a relatively small share of memory sales overall. But there are terrestrial applications for rad–hard memories, including avionic and other applications that require military standard temperature grades reaching from –55°C to 125°C.
In fact, he says, the new FRAM device was originally designed with commercial industrial automotive applications in mind. “We elevated it into higher reliability segments, like military or defense and space because of the capability of this technology.” Other terrestrial applications include implantable medical devices, which in some cases also need to be radiation tolerant.
FRAM is one of several emerging memories that have been around for decades, and it continues to draw interest due to its non–volatility and low power consumption, including its low switching energy, which means a very small amount of energy is required for programing. Its inherent reliability is also critical for space applications, which value predictable behavior from memory in what is a harsh, airless, and unpredictable environment.
Copyright © 2019 CST, Inc. All Rights Reserved