A continuous-time field programmable analog array with 1 GHz GBW

Abstract

This paper presents a vastly reconfigurable Field Programmable Analog Array (FPAA) for the instantiation of continuous-time (CT) analog filters up to 7th order. The circuit manufactured in a 90 nm CMOS technology contains 55 digitally tunable Gm-cells connected in a hexagonal network topology. Each Gm-cell is coarsely tunable by parallel connection of 1 to 6 unit-OTAs and smoothly tunable by a very area efficient 10 bit charge redistribution DAC adjusting the bias current. The Gm-cell corner frequency can be set to exceed 1 GHz bandwidth, which allows a huge amount of reconfigurable filters with almost continuously tunable corner frequencies from below 1 MHz to beyond 1 GHz.