Design of a flash analog-to-digital converter using threshold inverter quantization (TIQ) technique

• Main Author: Murni Hasan.
• Other Authors: Siek Liter
• Format: Final Year Project
• Language: English
• Published: 2010
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Electronic circuits
• Online Access: http://hdl.handle.net/10356/40360
• Institution: Nanyang Technological University

The analog-to-digital converter (ADC) is an essential part of system-on-chip (SoC) products because it bridges the gap between the analog physical world and the digital logical world. In the digital domain, low power and low voltage requirements are becoming more important issues as the channel length of MOSFET shrinks below 0.25 sub-micron values. This project implements the technique called Threshold Inverter Quantization (TIQ) in the design of a flash Analog-to-Digital Converter (ADC). This TIQ technique uses CMOS inverter as comparator in the ADC. Threshold voltage (Vm) of the inverters is used as reference voltage of the comparator. This threshold voltage on CMOS inverter is changed accordingly by transistor sizing on both PMOS transistor and NMOS transistor. However, CMOS inverter is susceptible to the process and the temperature variation. A variation in the temperature or in the process would make the threshold voltage change. Thus, this project eventually presents another design whose comparator uses a self-tuned inverter. This self-tuned inverter is insensitive to the temperature variation as well as the process variation compared to the CMOS inverter. Detailed analysis is performed for both designs to compare the performance between these two designs.