期刊名称：International Journal of VLSI Design & Communication Systems
印刷版ISSN：0976-1527
电子版ISSN：0976-1357
出版年度：2012
卷号：3
期号：2
出版社：Academy & Industry Research Collaboration Center (AIRCC)
摘要：This paper proposes the Flash ADC design using Quantized Differential Comparator and fat tree encoder. This approach explores the use of a systematically incorporated input offset voltage in a differential amplifier for quantizing the reference voltages necessary for Flash ADC architectures, therefore eliminating the need for a passive resistor array for the purpose. This approach allows very small voltage comparison and complete elimination of resistor ladder circuit. The thermometer code-to-binary code encoder has become the bottleneck of the ultra-high speed flash ADCs. In this paper, the fat tree thermometer code to-binary code encoder is used for the ultra high speed flash ADCs. The simulation and the implementation results shows that the fat tree encoder performs the commonly used ROM encoder in terms of speed and power for the 6 bit CMOS flash ADC case. The speed is improved by almost a factor of 2 when using the fat tree encoder, which in fact demonstrates the fat tree encoder and it is an effective solution for the bottleneck problem in ultra-high speed ADCs.The design has been carried out for the 0.18um technology using CADENCE tool.
关键词：TIQ; FAT TREE TC-BC ENCODER; CMOS; ANALOG TO DIGITAL CONVERTER.
