Design And Simulation Of ADC’s Circuit Of6-bit And100MS/s

In today’s society, ADC plays a more and more important role in the areasof military industry, aerospace, biotechnology and health. As the bridge ofareas of analog world and digital world—ADC’s parameters determine theperformance level which the electronic equipment has. As a rigid demand, thevalue of high-speed, high-precision, low-power, small-size, andhigh-integration is continuously optimized.Based on the technology, this article designs ADC of100MS/s in speedand6-bit for accuracy.There are three modules in this ADC including resistor network,comparator and encoder. The comparator and encoder are cores. Firstly, itmentions conversion speed and accuracy in the article.it selects fully parallelADC, folding and interpolating ADC and other types to compare. It also takesseveral methods to filter two indicators of conversion speed and precision andit chooses a fully parallel ADC as a model.Software simulation results, the gain pre-amplifier open-loop DC is14.54dB, bandwidth of-3dB is1.189GHz.It meets the needs of ADC well.During encoder design, it uses a "second conversion" mode to eliminatepossible metastability circuit,(change thermometer code into a Gray code, andthen change Gray code into binary code). Through circuit simulation, the resultis correct.In spectral analysis for the entire circuit, SNDR is32.56dB, SFDR is42.49dB and ENOB is5.116bit.