The Analysis on the Parasitic Capacitors Effect of the Fully Differential Architecture of SAR ADC
This paper presents an analysis on the parasitic capacitors effect of the fully differential architecture to provide common-mode rejection. The parasitic capacitors of differential comparator inputs has no effect on the resolution, however, the difference of comparator input parasitic capacitors may has great effect on the resolution. The relationship between the unity capacitor and the parasitic capacitors of the differential comparator inputs is analyzed by giving precise theoretical demonstration. Therefore, a theoretical basis is provided for designers to choose appropriate unity capacitor, process and layout in the design of SAR SAD with fully differential structure.
L. Sun et al., "The Analysis on the Parasitic Capacitors Effect of the Fully Differential Architecture of SAR ADC", Applied Mechanics and Materials, Vols. 20-23, pp. 342-345, 2010