Measurement Of 16-bit Delta-sigma Adc Design

Sigma-Delta ADC, not only has adopted the technology of oversampling, but also adopted the technology of noise modulation, that modulate the quantization noise in the baseband to the high-frequency area. It increases the SNR in baseband, and that is to say it has increased the effective quantization number of the converter. Because of the modulation technology, it makes Sigma-Delta ADC allow to use one bit comparator, and it has simplified the circuit of the analog part greatly. Because adopt higher sampling rate, the conversion speed of Sigma-Delta ADC is relatively low. The characteristics of high resolution and lower conversion speed, make Sigma-Delta ADC very suitable for measurement.This thesis analyzes the development of Sigma-Delta ADC technology and the trend, and combining the actual conditions, has put forward the function and performance requirement of Sigma-Delta ADC that is used for measuring. Then according to this designing requirement, this thesis has described the design process from system to circuits in detail. In the design of system, has considered the influence of different non-ideal factors especially, and the power consumption, and has proposed how to make the design to meet the performance requirement under the influence of non-ideal factors, and how to reduce the power consumption. In addition, according to the characteristics of measuring ADC, the author considered the realization of PGA. Finally, combining characteristics of design, put forward performance requirement of each circuit block in the design through simulation. In the circuit design, mainly analyzed and compared all kinds of amplifier used for realizing integrator, and adopted the chopper stabilization technology to eliminate low frequency noise. Finally, provide one amplifier satisfying design requirement.Through the systematic simulation of circuit level, has proved the designed ADC in this thesis having 16-bit precision when PGA is equal to 1,, and function of PGA.