Noise-driven architectures toward beyond CMOS LSIs with failure-prone nano-electronic devices

We investigated the implications of noises in a 1-bit analog-to-digital (pulse-density) converter consisting of single-electron devices. The proposed circuit architecture exploits fabrication mismatches (noises) to improve the performance of the pulse-density modulator. The modulator consists of three single-electron circuits that receive the same input and are connected to a common output. The output is inhibitorily fedback to the three circuits through a capacitive coupling, tuned to obtain a winners-share-all operation. The circuit performance was evaluated through Monte-Carlo based computer simulations. We demonstrate that the proposed circuit possesses noise-shaping characteristics, where the output signal and noises are separated into low and high frequency bands, respectively. This significantly improved the signal-to-noise ratio (SNR) by 4.34 dB in the noisy network, as compared to the case where the feedback and noises were not employed. The noise-shaping properties are as a result of i) the inhibitory feedback between the output and the single-electron circuits, and ii) noises (originating from device fabrication mismatches and thermally induced tunneling events) introduced into the network. 1