After the physical signal is converted to the electric domain, filtered and amplified, it must be quantized and converted into a digital word. The analog to digital conversion can be performed following many different approaches; the chosen one should take into account various aspects, like application specifications and signal properties. In our case, the main constraints come from the technology of TFTs on foil. In this chapter, circuit implementation for some building blocks commonly used for data conversion according to the scheme of Fig. 5.2 will be proposed: first a synchronous comparator and then a current-steering digital-to-analog converter. In the last part of this chapter, a complete integrating analog-to-digital converter is ana...