Fully-Digital Self-Calibrating Decoder with Sub-µW, 1.6fJ/convstep and 0.0075mm2 per Receptor for Scaling to Human-Like Tactile Sensing Density

This work presents an area- and energy-efficient decoder for tactile e-skin sensing encoding to scale up receptor density to the human scale. A fully-digital signal-adaptive receptor interface and event decoder architecture are introduced, leveraging temporal/spatial tactile signal sparsity to dynamically reduce activity and time resolution at negligible accuracy degradation. A novel reference-less self-calibrating senseamp is introduced to cancel offset by exploiting the statistical balance of spread-spectrum tactile pulses and noise. The 40nm testchip shows 1.6-fJ/convstep energy (0.0075mm2 area) per receptor with 50X (5X) improvement over prior art, and 80-receptor e-skin aggregation on a single pad.