Ultra-low Power VCO-ADC Design

The trends of medical devices on miniaturization, low power, and high precision have ahigher technical requirement for IC design.There are two objectives of this thesis:(1) One is based on the static characteristics anddynamic characteristics of ADC, in the compromise design and optimization designconcept, to extract the FOM function of ADC and build the base for the architecture ofVCO in ADC chip design;(2) Another is compared with the known architecture of ADCchips in advantages and disadvantages, to design the ultra-low power VCO ADC chip andevaluate the performance according to the methodology of the VCO structure, and then topropose the optimization proposals for layout design.Four parts of my works include:(1) The characteristic parameters of ADC chips wereintroduced, and the known structures of ADC were compared and analyzed. Based on that,the new FOM function for ADC was proposed to guide the whole design;(2) Focused onthe design methodology of the VCO ADC about time interleaved method, a comparativestudy in the three design conditions was shown, with establishing the conversion functiony[n] from analog signal to digital signal;(3) Using the known design methodology, thevarious modules of VCO ADC were designed, mainly included the modules of S/H, VCO,Reset Counter and so on. The complete principle diagram of circuit design was given at theend of the chapter;(4) HSPICE model was built with the nets table coming from Cadencesoftware platform, and with the evaluation of the our FOM function, the simulation resultswere checked repeatedly. The optimization scheme and layout design consideration wereprovided in the end.The typical research results show the power consumption of12bit VCO ADC is notmore than5μW in1.2V power supply and it can reach the level of nW in supply powerdown to0.55V. The experiments’ conclusions are: Based on the VCO ADC circuit, this work analyzesthe low power schemes for each module and summarizes the aspects of low powerconsumption in previous methods of ADC design for proposing the ultra-low powerconsumption scheme. It not only provides technical support for the optimization of medicalelectronic equipment, but also achieves the social philosophy for energy saving, lowcarbon accordingly.