Successive approximation analog-to-digital converter with digital enhancement technology, circuit and equipment

Abstract

The invention provides a successive approximation type analog-to-digital converter with a digital enhancement technology, a circuit and equipment, and the converter is characterized in that an input signal VIN end is connected with one end of a sampling switch SW and one end of a sampling clock, the other end of the sampling switch SW and the other end of the sampling clock are connected with a mixed structure DAC, the mixed structure DAC is connected with the negative electrode input end of a comparator, and the negative electrode input end of the comparator is connected with the output end of the comparator. An input common-mode voltage VCM is connected with the positive electrode input end of the comparator, the output end of the comparator is connected with the SAR logic, the SAR logic is connected with the DWA algorithm module and the DWA clock and mixed structure DAC, and the SAR logic outputs an ADC code stream ADCOUT. According to the successive approximation type analog-to-digital converter with the digital enhancement technology, the digital DWA algorithm is easy to implement, a pointer needed by the DWA algorithm can be directly obtained from the main ADC, an auxiliary ADC is not used, and the power consumption and the area of a circuit are saved to a great extent.

Description

technical field [0001] The invention relates to the field of analog-to-digital converter design, in particular to a successive approximation analog-to-digital converter with digital enhancement technology, a circuit and a device. Background technique [0002] The analog-to-digital converter is one of the most important parts of a signal processing system. In a signal processing system, some parts process analog signals, and some parts process digital signals, which requires that the two signals need to be converted back and forth, so the analog-to-digital converter is a very important part of the signal processing system. SAR-ADC is widely used because of its advantages of low power consumption and simple structure. With the development of science and technology, higher requirements are placed on the conversion accuracy of SAR-ADC in many fields. However, the nonlinear error caused by the mismatch between DAC units in SAR-ADC severely limits the conversion accuracy of SAR-A...

AI Technical Summary

Problems solved by technology

This implementation scheme uses error shaping in the low bits to realize the mismatch shaping of the DAC unit. The mismatch shaping needs to be completed by the loop filter, which increases the complexity of the circuit.

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