A micropower analog-to-digital converter and an algorithm for an interface system for an infrared imaging system
Date of Issue2009
School of Electrical and Electronic Engineering
Centre for Integrated Circuits and Systems
This project is part of an on-going research collaboration between MIT and NTU on the development of a novel imaging system – a Multispectral Infrared Detector Arrays (MIDAS) on Read-Out Integrated Circuit (ROIC). The project pertains to a design of a novel micropower monolithic 12-bit Successive Approximation Register (SAR) Analog-to-Digital Converter (ADC) for ROIC and a realization of novel image reading algorithms for the interface between the MIDAS-on- ROIC and a display. Of specific interest, a micropower ADC that is integrated onto ROIC is a dominant factor for the design a low-power and low-noise image system. Moreover, the vertically stacked image sensors in MIDAS (against the conventional planar image sensors) require a set of completely new interface algorithms. In the SAR-ADC design, a novel hybrid technique of voltage scaling and capacitive matching is proposed to improve the matching of on-chip resistors and capacitors, hence achieving the 12-bit resolution without expensive post-fabrication process. Further, a highly sensitive and high speed micropower comparator together with a simple and effective SAR logic circuit is also proposed. On the basis of computer simulations, the proposed SAR-ADC can achieve ultra low power consumption in operation (188uW with 3.3V voltage supply). Layout of the proposed SAR-ADC is partially realized. A novel interface algorithm for vertically-stacked image sensor is realized in MATLAB on the basis of the standard gamma correction, resulting in a linear conversion interface between the MIDAS-on-ROIC and the display. The proposed MATLAB algorithms are suitable for both still image display and video display.
DRNTU::Engineering::Electrical and electronic engineering::Electronic circuits
Final Year Project (FYP)
Nanyang Technological University