Journal of Undergraduate Research


ultra-low power analog-to-digital coverter, neutral signal recording


Ira A. Fulton College of Engineering and Technology


Electrical and Computer Engineering


Brain diseases, such as depression and strokes, affect an ever-increasing number of the human population. Much scientific research has been devoted to finding ways towards alleviating the negative symptoms of these diseases. However, much more research must be conducted before these maladies are no longer a problem. Neural implantable devices are an essential part of such research. These tiny, electronic devices monitor electrical brain activity and wirelessly transmit the collected data to computers so scientists can analyze it. A common issue with these neural recording devices is battery life. Current technology allows for a battery to last only 3-5 years. Often, the devices need to be replaced, which requires invasive brain surgery and significant medical cost. Our ongoing research project is to design an ultra-low power Analog-to-Digital Converter (ADC) that can be used in a low power neural recording device to minimize invasive replacement surgeries. Our primary way of achieving this is to design an ADC that uses a 0.2V power supply. The current state-of-the art ADCs use a minimum of a 0.3V power supply. Therefore, our ADC will drastically improve on current designs. However, when such a low supply voltage is used, the ADC speed performance is extremely degraded. We have chosen to design a Successive Approximation Register (SAR) ADC because that design has an inherent low power consumption. In our SAR design, we use various circuit design techniques to improve the speed of the ADC circuitry, especially the comparator.