A 0.17-mm2 3.19-nJ/transform 256-point fast fourier transform core based on spatiotemporally fine-grained active leakage suppression

This paper presents an ultra-low energy and compact Fast Fourier Transform (FFT) processor suitable for pervasive sensing systems. To achieve high energy efficiency and small area, we design area-efficient memory-based architecture and equip it with two proposed techniques: (i) spatiotemporally finegrained active leakage suppression for sub-threshold voltage (sub-VTH) combinational logic and (ii) spatiotemporally finegrained performance boosting for ultra-low leakage sub-VTH memory. The prototyped chip, implemented in a 65-nm General-Purpose CMOS, consumes 3.19 nJ per FFT transform and requires 0.17 mm
²
area while achieving 1.2 MS/s.