Hardware Prototype of a Time-Encoding Sub-Nyquist ADC

Analog-to-digital converters (ADCs) are key components of digital signal processing. Classical samplers in this framework are controlled by a global clock. At high sampling rates, clocks are expensive and power-hungry, thus increasing the cost and energy consumption of ADCs. It is, therefore, desirable to sample using a clock-less ADC at the lowest possible rate. An integrate-and-fire time-encoding machine (IF-TEM) is a time-based power-efficient asynchronous design that is not synced to a global clock. Finite-rate-of-innovation (FRI) signals, ubiquitous in various applications, have fewer degrees of freedom than the signal's Nyquist rate, enabling sub-Nyquist sampling signal models. This work proposes a power-efficient IF-TEM ADC architecture and a sub-Nyquist sampling and FRI signal recovery. Using an IF-TEM, we implement in hardware the first sub-Nyquist time-based sampler, with a detailed hardware design. Our approach provides a robust and accurate method for estimating FRI parameters from IF-TEM data. The proposed hardware and reconstruction technique achieves parameter retrieval with errors up to -25 dB while operating at approximately one-tenth of the Nyquist rate, enabling low-power ADC architectures.