Low-power FRAM with integrated counter function, for energy harvesting apps

December 08, 2014 // By Graham Prophet
Fujitsu Semiconductor’s MB85RDP16LX is an ultra-low-power FRAM device with an integrated binary counter function. It incorporates multiple optimisations to reduce energy consumption to less than 10% of that required by standard FRAM solutions.

With the MB85RDP16LX, Fujitsu is targeting industrial automation applications involving energy harvesting for rotary encoders, motor control and sensors. The ultra-low-power device can enable self-powering solutions such as the Wiegand wire-based platform being offered by iC-Haus.

Significant energy savings have been achieved by integrating the counter function into the FRAM device. Conventional system environments using standard memory require the MCU to read data from the memory device before performing computation and then writing new data back to the memory to complete the counting operation. In contrast, MB85RDP16LX replaces these separate read/write operations with a single command from the MCU, resulting in energy savings of up to 94%.

The power-up time of MB85RDP16LX has been optimised to 5 µsec, which is 38 times faster than standard FRAM devices. This enables extremely fast device wake-up while consuming as little energy as possible.

MB85RDP16LX can be connected via single- and dual-SPI interfaces. A dual SPI interface offers customers the option of halving the clock frequency: this achieves further power saving gains without impacting performance.

To satisfy the broad temperature ranges required by the industrial automation market, MB85RDP16LX has been specified for an operating temperature range of -40–105 °C without compromising its 10-year data retention time.

MB85RDP16LX is being offered in an SON-8 package with dimensions of 2 x 3 mm; compared to typical SOP-8 packages, over 80% of the memory's PCB space can be saved.

Fujitsu; http://fujitsu-semiconductor.eu