SCIENTIFIC RESEARCH AND ESSAYS, cilt.6, ss.351-362, 2011 (SCI İndekslerine Giren Dergi)
This paper presents design and implementation of a 9-bit folding and interpolation ADC using 0.35 mu m CMOS C35B4 model under AMS-HIT Kit Library. The complete system consists of two main blocks. One of them is 4-bit flash ADC, which is based on the so-called threshold inverter quantization (TIQ) technique. This part forms the coarse part of the data conversion process. The second one is the 5-bit fine ADC part of the converter. This block includes comparator, analog pre-processing and interpolation units. The designed converter works with 5 V power supply, and has analog input range of 3.4 Vpp. Analog input bandwidth is 1 MHz with clock frequency of 2 GHz for the digital part. The linearity measures of the converter include 2.9 LSB of DNL and 6.3 LSB of INL. The main purpose of this work is to investigate the possibility of employing TIQ technique in designing folding and interpolation type of ADCs. Although, the linearity measures are not satisfying for 9-bit case, the authors believe that this case study will serve as a preferred reference for the researchers who are willing to use TIQ technique in designing fast ADCs other than flash scheme especially.