The Design of a Sigma-Delta Analog-to-Digital Converter for Voice-Based Door Access Control Systems.

• Main Authors: YANG, XIN-YU, 楊心瑜
• Other Authors: LEE, DA-HUEI
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/b24a66

碩士 === 南臺科技大學 === 電子工程系 === 107 === Intelligent technology is the leading trend in the quickening pace of technology advancements. Not only light bulbs, refrigerators, watches, and other appliances and gadgets are part of the smart life movement, but also the door locks as well. Rope knots for doors have now become the blade locks and pin tumbler locks commonly seen today. What remains unchanged is the key that one carries along. Keys can secure homes but are susceptible to loss, and its weight may be burdensome. Also, traditional door locks have similar designs, and thieves with some practice can pick open locks easily and gain access. In response, this study proposes the combination of mobile devices and voice information to form a multi-layered security mechanism for home safety. This study aims to make traditional door locks more convenient, mainly dealing with the burden and risk of reduplication associated with physical keys. The design is to use mobile devices as a medium to create a three-layer security prevention mechanism. The first layer is wireless communication technology pairing, after which comes the second layer based on the pairing of voice decoding pairing, and completes with password entry. Such a safety mechanism is not easy to break, and can both increase the level of house security while eliminating the inconvenience associated with physical keys. The study uses a sound detection sensor as the audio receiver component. Upon receiving the audio signal, it is necessary to convert its analog signal to digital, then conduct analytical decoding through a back-end system. Therefore, this study employs a high resolution and low-power Sigma-Delta analog-to-digital converter for signal conversion. The circuit system uses the 0.18μm CMOS process parameters provided by UMC for design and simulation. When the sampling frequency is at 2.5 MHz, and the supersampling frequency is at 128, the signal to noise ratio can reach 97.7dB, equivalent to 15 effective number of bits, with consumed power at 2.63mW. Keywords: voice-based door lock, home security, intelligent lock,Sigma-Delta analog-to-digital converter, Sigma-Delta Modulator