A Photoacoustic Receiver System-on-Chip with a Novel Correlation Detection Technique Based on Early-and-Late Tracking

Flexible and wearable devices are emerging with the developing of the sensors and IoT (internet of the things). The power consumption and volume of such devices are dominant limitations for wearable feature in various applications. To meet the requirements, a photoacoustic receiver system-on-chip (SoC) is developed and fabricated with a novel correlation detection technique based on the early-and-late tracking. Through this method, output SNR of the receiver can be significantly improved. For this, a low power and high sensitivity analog front-end (AFE) with a noise shaping (NS) SAR ADC is implemented. As oversampling is necessary for the accurate delay of digital processing, noise shaping technique is implemented in the SAR ADC. Simulation results show that, the AFE achieves 70 dB dynamic range and 20 mu V sensitivity for about 30 dB output SNR. The SAR ADC can obtain 71 dB SNDR under 50MSps sampling rate with the aid of the NS technique. Based on the analog circuits design, the digital part for the detecting technique is also implemented on chip. The whole power consumption is about 15 mW on the TSMC 65 nm CMOS process.