A New Universal Second-Order Filter using Configurable Analog Building Blocks (CABs) for Filed-Programmable Analogue Arrays

In this paper, the design of a universal second-order filter using configurable analog blocks (CABs) for field programmable analog arrays is presented. The configurable blocks are capable of performing integration, differentiation, amplification, log, anti-log, add and negate functions. To maintain high frequency operation, the programmability and configurability of the blocks are achieved by digitally modifying the block s biasing conditions. Using at most four CABs, this article shows that it is possible to design a versatile second-order filter realizing all the standard five filter functions; lowpass, highpass, bandpass, notch and allpass. SPICE simulation results using practical bipolar junction transistor (BJT) parameters confirm the feasibility of using the CABs in designing second-order filters.