A Second-Order ΣΔ ADC with Oxide TFTs @ FCT-UNL
- 588 Downloads
The capability of new technologies, such as oxide thin-film transistors (TFTs) is reinforced when they are successfully integrated in circuits or systems with a considerable level of complexity. In the particular case of this study, sputtered indium-gallium-zinc oxide (IGZO) TFTs are used to design, simulate and produce an analog-to-digital converter (ADC), demonstrating the potential of this technology namely in terms of lower processing temperature and costs and excellent performance, typically far superior to a-Si and organics and comparable to LTPS.
In this chapter, the optimized IGZO TFTs with multilayer and multicomponent dielectric, based on Ta2O5 and SiO2, are used to design a sigma-delta (\( \Sigma \Delta \)) modulator (\( \Sigma \Delta M \)), with a particular attention to the comparator, the active block in the circuit. The circuits are simulated using commercial electronic design automation (EDA) tools, which will be briefly referred. Furthermore, some layout considerations and hints for a successful fabrication are also provided.
KeywordsPrint Circuit Board Electrical Simulation Wire Bonding Process Electronic Design Automation Oxide TFTs
- 1.T.C. Carusone, D. Johns, K. Martin, Analog Integrated Circuit Design, 2nd ed. (Wiley, 2011). http://eu.wiley.com/WileyCDA/WileyTitle/productCd-EHEP002039.html
- 3.J.L.A. de Melo, F. Querido, N. Paulino, J. Goes, A 0.4-V 410-nW opamp-less continuous-time \( \varSigma \varDelta \) modulator for biomedical applications, in 2014 IEEE International Symposium on Circuits and Systems (ISCAS) (IEEE, Melbourne, 2014) pp. 1340–1343Google Scholar
- 4.J.L.A. de Melo, J. Goes, N. Paulino, A 0.7 V 256 μW \( \varDelta \varSigma \) modulator with passive RC integrators achieving 76 dB DR in 2 MHz BW, in 2015 Symposium on VLSI Circuits (VLSI Circuits) (IEEE, Kyoto, 2015) pp. C290–C291Google Scholar
- 5.J.L.A. De Melo, A low power 1-MHz continuous-time \( \varSigma \varDelta \) M using a passive loop filter designed with a genetic algorithm tool, in Proceedings - IEEE International Symposium on Circuits and Systems, vol. 1 (2013), pp. 586–589Google Scholar
- 6.J.L.A. de Melo, B. Nowacki, N. Paulino, J. Goes, Design methodology for Sigma-Delta modulators based on a genetic algorithm using hybrid cost functions, in 2012 IEEE International Symposium on Circuits and Systems (IEEE, Seoul, 2012) pp. 301–304Google Scholar
- 7.A. Dey, D.R. Allee, Amorphous silicon 5 bit flash analog to digital converter, in 2012 IEEE Custom Integrated Circuits Conference (IEEE, San Jose, 2012)Google Scholar