Design of high-speed and 6-bit flash ADC module for non-contact vital sign signal processing in biomedical application

Abstract

The signal processing is the primary factor for improving the accuracy of bio signals in electronic devices with respect to speed and resolution. The ADC is often called the heart of the electronics processing system. Without the ADC module, the device cannot proceed to further processing stages and becomes non-functional. In biomedical applications, healthcare service providers remotely monitor patients using non-contact vital sign detection and signal monitoring through CW Doppler radar of 2.45 GHz. The system collects tiny signals remotely, with HR signals of (0.2–0.5)Hz and RR signals of (0.3–0.7)Hz. Recovering these signals from the received data, containing clutters and noise, is a challenging task that requires a high-speed, high-resolution, and accurate-based system. The SAR-ADC has existing problems with high speed and bit resolution, system performance, and accuracy, which are overcome in the flash ADC with reduced hardware. The received signal is further processed using the DAQ system. The system uses a 6-bit 1GS/s flash ADC for enhanced system performance. Simulation results show an INL of -0.49/+0.76 LSB and DNL of -0.65/+0.59 LSB, respectively. At -0.3 dBFS and a 1 kHz sinusoidal signal, the SNDR is 47dB (6.4 ENOB). The system operates at power level of 96.08uW with a supply voltage of 1.6 V. The implementation is carried out using simulation tools such as Cadence Virtuoso, and MATLAB platforms.