Circuits and algorithms for pipelined ADCs in scaled CMOS technologies

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.MIT Barker Engineering Library copy: printed in pages.Also issued printed in pages.Includes bibliographical references (leaves 179-184).CMOS technology scaling is creating significant issues for analog circuit design. For example, reduced signal swing and device gain make it increasingly difficult to realize high-speed, high-gain feedback loops traditionally used in switched capacitor circuits. This research involves two complementary methods for addressing scaling issues. First is the development of two blind digital calibration techniques. Decision Boundary Gap Estimation (DBGE) removes static non-linearities and Chopper Offset Estimation (COE) nulls offsets in pipelined ADCs. Second is the development of circuits for a new architecture called zero-crossing based circuits (ZCBC) that is more amenable to scaling trends. To demonstrate these circuits and algorithms, two different ADCs were designed: an 8 bit, 200MS/s in TSMC 180nm technology, and a 12 bit, 50 MS/s in IBM 90nm technology. Together these techniques can be enabling technologies for both pipelined ADCs and general mixed signal design in deep sub-micron technologies.by Lane Gearle Brooks.Ph.D

Amplitude and frequency demodulation controller for microelectromechanical systems accelerometer

Thesis (M.Eng. and S.B.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2001.Includes bibliographical references (p. 121-122).Draper Laboratory is developing a high precision MEMS accelerometer. This thesis describes and analyzes the electronics which produce the acceleration estimate and control the actuators within the sensor. The Vector Readout method of amplitude and frequency demodulation is described and shown to be a high precision, environmentally stable method of demodulation. The Vector Readout method of demodulation uses a Hilbert Transform filter and the CORDIC algorithm to simultaneously estimate both the amplitude and phase of a signal. A feedback controller is designed to hold the oscillation of a mass resonator at a constant amplitude.by Lane Gearle Brooks.M.Eng.and S.B