Reconfigurable Array for Analog Applications

Abstract

In this paper, a novel field-programmable analog array (FPAA) fabric consisting of a 6x6 matrix of configurable analog blocks (CABs) is proposed. The implementation of programmable CABs eliminates the use of fixed analog sub-circuits. A unique routing strategy is developed within the CAB units that supports both differential and single-ended mode circuit configurations. The bandwidth limitation due to the routing switches of each individual CAB unit is compensated for through the use of a switch-less routing network between CABs. Algorithms and methodologies are developed to facilitate rapid implementation of analog circuits on the FPAA. The proposed FPAA fabric provides high operating speeds as compared to existing FPAA topologies, while providing greater configuration in the CAB units as compared to switch-less FPAAs. The FPAA core includes 498 programming switches and 14 global switchless interconnects, while occupying an area of 0.1 mm2 in a 65 nm CMOS process. The characteristic power consumption is approximately 24.6 mW for a supply voltage of 1.2 V. Circuits implemented on the proposed FPAA fabric include operational amplifiers (op amps), filters, oscillators, and frequency dividers. The reconfigured bandpass filter provides a center frequency of approximately 1.5 GHz, while the synthesized ring-oscillator and frequency divider support operating frequencies of up to 500 MHz.