An A/D interface based on ∑△ modulator for thermal vacuum sensor ASICs  

作　　者：李金凤 唐祯安 

机构地区：[1]Department of Electronic Engineering,Dalian University of Technology [2]School of Information Engineering,Shenyang Institute of Chemical Technology

出　　处：《Journal of Semiconductors》2010年第7期115-120,共6页半导体学报（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(No.90607003).

摘　　要：A newΣΔmodulator architecture for thermal vacuum sensor ASICs is proposed.The micro-hotplate thermal vacuum sensor fabricated by surface-micrornachining technology can detect the gas pressure from 1 to 10;Pa. The amplified differential output voltage signal of the sensor feeds to theΣΔmodulator to be converted into digital domain.The presentedΣΔmodulator makes use of a feed-forward path to suppress the harmonic distortions and attain high linearity.Compared with other feed-forward architectures presented before,the circuit complexity,chip area and power dissipation of the proposed architecture are significantly decreased.The correlated double sampling technique is introduced in the 1st integrator to reduce the flicker noise.The measurement results demonstrate that the modulator achieves an SNDR of 79.7 dB and a DR of 80 dB over a bandwidth of 7.8 kHz at a sampling rate of 4 MHz.The circuit has been fabricated in a 0.5μm 2P3M standard CMOS technology.It occupies an area of 5 mm;and dissipates 9 mW from a single 3 V power supply.The performance of the modulator meets the requirements of the considered application.A newΣΔmodulator architecture for thermal vacuum sensor ASICs is proposed.The micro-hotplate thermal vacuum sensor fabricated by surface-micrornachining technology can detect the gas pressure from 1 to 10~5 Pa. The amplified differential output voltage signal of the sensor feeds to theΣΔmodulator to be converted into digital domain.The presentedΣΔmodulator makes use of a feed-forward path to suppress the harmonic distortions and attain high linearity.Compared with other feed-forward architectures presented before,the circuit complexity,chip area and power dissipation of the proposed architecture are significantly decreased.The correlated double sampling technique is introduced in the 1st integrator to reduce the flicker noise.The measurement results demonstrate that the modulator achieves an SNDR of 79.7 dB and a DR of 80 dB over a bandwidth of 7.8 kHz at a sampling rate of 4 MHz.The circuit has been fabricated in a 0.5μm 2P3M standard CMOS technology.It occupies an area of 5 mm^2 and dissipates 9 mW from a single 3 V power supply.The performance of the modulator meets the requirements of the considered application.

关 键 词：integrated sensor analog to digital conversion feed-forward path correlated double sampling ΣΔmodulator 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]