A Novel Analog to Digital Conversion Concept with Crosstalk Computing

Abstract

Analog to Digital Converters (ADCs) is the core component of computing systems forming a link between the external stimuli and digital microprocessor operations. Current CMOS based fast ADCs are difficult to scale due to the reliance on transistor sizing and high voltage operations. They also suffer from high power consumption. In this paper, we introduce a novel ADC design which uses the deterministic signal interference between metal lines as a mechanism for signal conversion. In contrast to CMOS ADCs, our approach uses a simple crosstalk tree network of metal lines to convert sampled analog levels to digital code. Here, the sampled analog signal is passed through an input metal line which is capacitively coupled to a series of metal lines in a tree-like layout, and the coupled voltages on the edge of the tree (the leaves) determine the output. The resolution is dependent on the number of branches. We show 2-bit and 3-bit ADC implemented through this mechanism at 16n technology node. Our results indicate the possibility of huge power savings with Crosstalk ADCs in comparison to CMOS; for 2-bit and 3-bit ADCs the power consumption was found to be 43.51μW and 96.74μW respectively at 50M Hz sampling frequency.