Researchers at the Public University of Navarra have developed what they describe as an ultra low consumption a/d converter. The 8bit charge redistribution successive approximation register (SAR) device is intended for use in wireless sensor nodes, where it can be powered by energy harvested from the environment.
The a/d converter, which has an area of around 1mm2 features a new capacitor switching procedure that reduces the average switching energy compared to previous approaches. Simulation and measurement results of a test chip operating at 100ksample/s are said to show a spurious free dynamic range of 55.63dB and a power consumption of 2.17µW. The work was presented at the 7th International Conference on Sensing Technology, held in Wellington in December 2013, with the authors – Professor Antonio López-Martín and engineering student Iñigo Cenoz-Villanueva – receiving the award for the best paper.