Instantiation of higher order filters on a continuous-time field-programmable analog array

Abstract

This work presents techniques for mapping various Gm-C filter topologies on a specialized field-programmable analog array (FPAA) for continuous-time filters. Through its unique hexagonal architecture, it is possible to map most well-known Gm-C filter topologies to the array, including cascaded biquads, simulated LC-ladders, as well as integrator feedback and feed-forward structures. Through tuning of the digitally programmable filter elements, the properties of the resulting filters, such as bandwidth, filter type or cutoff frequencies can be varied after the filter topology has been instantiated.