Design Of Digital Integrated Circuit For Gas Pressure Sensor Based On Micro-Hotplate

Thermal conduction gas pressure sensors are widely used in the fields of spaceflight, chemical industry, semi-conductor fabrication, foodstuff processing, electronic encapsulation and scientific researches. With the rapid development of MEMS (Micro-Electro- Mechanical Systems) and IC (Integrated Circuit) technology, integrated thermal conduction gas pressure micro-sensor becomes an important research area.In this thesis, according to the response characteristics of micro-hotplate gas pressure sensor, a system fabric of integrated gas pressure micro-sensors is developed, and efforts are focused on digital IC designing. Functions including sampling control, digital filter, air pressure testing, and the drive of LED (Light Emitting Diode), are intergrated in this integrated circuit. With the designed integrated circuit, the sensor voltage signal is sampled by ADS8401, and then is digitally filtered. Then gas pressure is output in real-time by LUT (Look Up Table) method, and displayed on the LEDs by dynamic scanning. Integrating this chip with a gas pressure micro-sensor and an AD chip can reduce the size and power consumption of measurement system, and can improve its performance.The key technology and design methodology of digital integrated circuit are introduced according to the design process of the digital integrated circuit. The system is designed using Verilog hardware describe language, simulated using Modelsim SE 5.8c of Mentor, then preliminary synthesized using QuartusII 4.0 of Altera and finally, the design is realized into ASIC(Application Specific Integrated Circuit) using EDA tool Synopsys. The design of the ASIC is as following: DC (Design Compiler) is used to synthesis the design. PT (Prime Time) is adopted to analyze the static time. Formality is adopted to implement formal verification. Astro is used to implement placement, routing and layout verification. The layout files in GDSII format for chip fabrication are obtained, and the design and verification of the digital integrated circuits are completed. Smic 0.18um standard CMOS technology and Artisan standard components are adopted in the synthesis and layout design.