Field programmable analog array: A boon for analog world

In analog chips designing, fabricating, and testing takes a lot of time, money and perfection. In contrast design of digital integrated circuits is fully automated now a day. Due to simpler nature of digital circuits, as compared to Analog circuits, leads to development of libraries and synthesis tools for fast synthesis of digital circuits. To reduce the cost and time-to-market CPLDs and FPGAs are generally used for prototyping of digital integrated circuits. But FPAAs i.e Field Programmable Analog Arrays are boon for designing of analog and mixed-signal Integrated Circuits because of rapid prototyping. FPAA is not only optimal for all solution in contrast to FPGAs but it also reduces the verification and designing cost. This again results from complex nature of analog circuits which needs factors like signal to noise ratio, bandwidth, frequency response, linearity etc. to be addressed. FPAAs are made using configurable analog blocks (CAB) and networks, which are used to provide required interconnection among Cabs. Like FPGAs, circuit functionality is much more sensitive to parasitics introduced by the programming devices in FPAA. So the design of FPAAs architecture and CABs are mutually dependent. To design an efficient FPAA, a designer needs to compromise between flexibility and the number of programmable switches in designing FPAA architectures and the CAB topologies. Various papers are studied for different topologies used in FPAAs and various applications designed with the use of FPAA.