Quanyuan Feng

High Linearity SAR ADC for Smart Sensor Applications

This paper presents a capacitive array optimization technique capable to improve the Spurious Free Dynamic Range (SFDR) and Signal-to-Noise-and-Distortion Ratio (SNDR) of Successive Approximation Register (SAR) Analog-to-Digital Converter (ADC) for smart sensor specifications. Monte Carlo simulation results show that the proposed optimization technique makes the SFDR, SNDR and (Signal-to-Noise Ratio) SNR better definitely concentrated, which means with a spread between maximum and minimum value much smaller than the one obtained by conventional calibration techniques. This gives rise to more stable and better performances. The averaged SFDR improves from 72.9 dB to 91.1 dB with σu = 0.4%, the 18.2 dB improvement required an off-line processing and a small digital logic circuits.This paper presents capacitive array optimization technique to improve the Spurious Free Dynamic Range (SFDR) and Signal-to-Noise-and-Distortion Ratio (SNDR) of Successive Approximation Register (SAR) Analog-to-Digital Converter (ADC) for smart sensor application. Monte Carlo simulation results show that capacitive array optimization technique proposed can make the SFDR, SNDR and (Signal-to-Noise Ratio) SNR more concentrated, which means the differences between maximum value and minimum value of SFDR, SNDR and SNR are much smaller than the conventional calibration techniques, more stable performance enhancement can be achieved, and the averaged SFDR is improved from 72.9 dB to 91.1 dB by using the capacitive array optimization method, 18.2 dB improvement of SFDR is obtained with only little expense of digital logic circuits, which makes it good choice for high resolution and high linearity smart sensing systems.

High-Resolution ADCs Design in Image Sensors

This paper presents design considerations for high-resolution and high-linearity ADCs for biomedical imaging applications. The work discusses how to improve dynamic specifications such as Spurious Free Dynamic Range (SFDR) and Signal-to-Noise-and-Distortion Ratio (SNDR) in ultra-low power and high-resolution analog-to-digital converters (ADCs) including successive approximation register (SAR) for biomedical imaging application. The results show that with broad range of mismatch error, the SFDR is enhanced by about 10 dB with the proposed performance enhancement technique, which makes it suitable for high resolution image sensors sensing systems.

Comparator Design in Sensors for Environmental Monitoring

This paper presents circuit design considerations of comparator in analog-to-digital converters (ADC) applied for a portable, low-cost and high performance nano-sensor chip which can be applied to detect the airborne magnetite pollution nano particulate matter (PM) for environmental monitoring. High-resolution ADC plays a vital important role in high perfor-mance nano-sensor, while high-resolution comparator is a key component in ADC. In this work, some important design issues related to comparators in analog-to-digital converters (ADCs) are discussed, simulation results show that the resolution of the comparator proposed can achieve 5µV , and it is appropriate for high-resolution application.

Design of Sensor System for Air Pollution Monitoring

In this work, we present the design of sensor platform for air pollution monitoring. During the design process, we took into account a lot of problems such as system architecture, power consumption and linearity consideration. ADC plays a vital important role in high-linearity sensor micro system, several practical techniques which can improve the performance and decrease power consumption of ADC are discussed in this paper.