System and Analog Front-End Design for Wireless Optogenetics and Marine Mammal Science

Abstract

The first part of this thesis will present a low-noise, low-power Analog Front-End (AFE) for acoustic and ocean pressure detection used in marine mammal science applications. First, the design of a test chip consisting of three AFE variations with a common two-stage amplifier will be analyzed. The primary goal for the first iteration chip was to explore the tradeoffs between noise and power as well as to perform basic interfacing with a hydrophone sensor; this in preparation for the second iteration system. The measured test results of this fabricated chip are discussed in detail. Second, a deployable system built upon the test chip and improved with several features such as power-gating, variable gain, and frequency scaling will be presented. This system includes digitization of sonar and pressure signals through an 8-bit successive approximation ADC. An SPI interface was added to the design in order to be compatible with a System-on-Chip developed by a collaborative team from the University of Virginia. In the second part of this work, a system for wireless optogenetics will be presented. First, an overview of the optogenetics science will be covered, as well as a brief description of the state-of-the-art stimulation systems used in this field. Next, a high-level overview of the proposed system will be presented followed by a detailed description of the main blocks. The last section will contain applicable metric measurements and the results obtained from an in-vivo experiment conducted using our system.