Doctoral Dissertations

Date of Award


Degree Type


Degree Name

Doctor of Philosophy


Electrical Engineering

Major Professor

Ethan Farquhar

Committee Members

Ben Blalock, Syed Islam, Suzanne Lenhart


This work describes a novel frequency based Current to Digital converter, which would be fully realizable on a single chip.

Biological systems make use of delay line techniques to compute many things critical to the life of an animal. Seeking to build up such a system, we are adapting the auditory localization circuit found in barn owls to detect and compute the magnitude of an input current.

The increasing drive to produce ultra low-power circuits necessitates the use of very small currents. Frequently these currents need to accurately measured, but current solutions typically involve off-chip measurements. These are usually slow, and moving a current off chip increases noise to the system. Moving a system such as this completely on chip will allow for precise measurement and control of bias currents, and it will allow for better compensation of some common transistor mismatch issues.

This project affords an extremely low power (100s nW) converter technology that is also very space efficient. The converter is completely asynchronous which yields ultra-low power standby operation [1].

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