A Low-Voltage Analog to Information Converter with Hybrid Quantization

Analog-to-information converters (AICs) provide sub-Nyquist sampling rates by signal bandwidth compression, leading to continuous charge accumulation within the circuit. The amplitude of the compressed signal sometimes exceeds the voltage range of the circuits, thereby impacting its precision. The incorporation of voltage boosting and interpolation into flash AIC is suggested to resolve this problem. A voltage boost method with a charge pump generates several reference levels for a comparator. The output of the comparator is subsequently segmented and quantified by hybrid domain quantization, resulting in an interpolated digital sequence. The experimental results demonstrate that the proposed flash AIC is capable of processing a signal with an amplitude range of 1 V while operating on a supply voltage of 0.8 V. It samples the signal at a maximum bandwidth of 25 MHz, at a rate of 12.5 MHz, and achieves 4-bit quantization through the use of a 1-bit comparator. Compared with the current AIC designs, the flash AIC achieves a 2x improvement in the Figure of Merit (FoM), while incurring only a negligible compromise on the reconstructed signal-to-noise ratio (RSNR).