Highly Efficient Comparator Design Automation for TIQ Flash A/D Converter

Insoo KIM  Jincheol YOO  JongSoo KIM  Kyusun CHOI 

Publication
IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences  Vol.E91-A  No.12  pp.3415-3422
Publication Date: 2008/12/01
Online ISSN: 1745-1337
Print ISSN: 0916-8508
Type of Manuscript: Special Section PAPER (Special Section on VLSI Design and CAD Algorithms)
Category: Physical Level Design
Keyword: 
flash A/D converter,  CMOS inverter,  comparator,  threshold inverter quantization (TIQ),  analog design automation, 

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Summary: 
Threshold Inverter Quantization (TIQ) technique has been gaining its importance in high speed flash A/D converters due to its fast data conversion speed. It eliminates the need of resistor ladders for reference voltages generation which requires substantial power consumption. The key to TIQ comparators design is to generate 2n - 1 different sized TIQ comparators for an n-bit A/D converter. This paper presents a highly efficient TIQ comparator design methodology based on an analytical model as well as SPICE simulation experimental model. One can find any sets of TIQ comparators efficiently using the proposed method. A 6-bit TIQ A/D converter has been designed in a 0.18 µm standard CMOS technology using the proposed method, and compared to the previous measured results in order to verify the proposed methodology.