IMEC’s ISSCC major breakthroughs
THE ISSCC (International solid-state Circuits Conference (ISSCC) was the event where IMEC nanotechnology R&D center elected to announce three major advances in technologies that will be used in wireless autonomous sensor nodes: (1) a read-out front-end for portable biopotential acquisition systems; (2) a fully integrated low-power UWB receiver for low-data-rate applications; and, (3) a high-speed analog-to-digital converter (ADC) with a record low-power consumption of 0.16pJ/conversion step. The ADC architecture has been implemented within the UWB receiver.
The three technology advances will benefit IMEC’s Human program, which addresses medical, lifestyle and entertainment applications.
The read-out front-end allows the extraction of bio-potential signals produced by portable electroencephalography (EEG), electrocardiography (ECG) and electromyography (EMG) systems. It is also suitable for autonomous applications. The front-end has an equivalent input referred noise of 60nV/Hz and a total power dissipation of 60µW.
EEG, ECG and EMG waves are µV-range signals that suffer from a large amount of common-mode (CM) interference. Furthermore, the bio-potential electrodes that are needed to view the signals generate a non-negligible offset. To achieve signal extraction, a front-end is needed with high CM rejection ratio (CMRR); low-noise, high-pass filter (HPF) characteristics; and configurability for bio-potentials originating from the heart, muscles or the brain. Very low power consumption is necessary to enable long-term power autonomy. The aim is to increase the patient’s autonomy and quality of life, as well as extending the devices to sports, entertainment, comfort monitoring, and other health and lifestyle products and services.
The bio-potential front-end, which was fabricated in a 0.5µm CMOS process through AMI Semiconductor, has a core area measuring less than 2mm2. It is capable of operating more than three years from two conventional AA batteries, making it ideal for autonomous applications.
