Noise-shaping pulse-density modulation in inhibitory neural networks with subthreshold neuron circuits

We designed subthreshold analog MOS circuits implementing an inhibitory network model that performs noise-shaping pulse-density modulation (PDM) with noisy neural elements. The aim of our research is to develop a possible ultralow-power delta–sigma type one-bit analog-to-digital converter. Through circuit simulations we confirmed that the signal-to-noise ratio (SNR) of the network was improved by 7.9 dB compared with that of the uncoupled network as a result of noise shaping.