Low-power-consumption SAR ADC based on common-mode level switch switching and working method thereof

Abstract

The invention relates to a low-power-consumption SAR ADC based on common-mode level switch switching, which comprises a bootstrap switch module, a sectional capacitor array module based on a common-mode level switch switching mode, a comparator module, an asynchronous time sequence module and a latch module which are connected in sequence, a switch switching module is arranged among the sectional capacitor array module based on the common-mode level switch switching mode, the asynchronous time sequence module and the latch module; the bootstrap switch module samples a VIN input signal and a VIP input signal to complete signal transmission; compared with the prior art, the low-power-consumption SAR ADC based on switching of the common-mode level switch is provided, the capacitor array module is of a sectional structure, the capacitor array switching mode based on the common-mode level can well avoid large-amplitude fluctuation of an input common-mode range, and the requirement for a comparator module is lowered.

Description

technical field [0001] The invention relates to the technical field of analog-to-digital converters, in particular to a low-power consumption SAR ADC based on common-mode level switching and a working method thereof. Background technique [0002] In recent years, with the development of electronic information technology and the maturity of digital signal processing technology, the extraction and utilization of massive information has been realized in the fields of big data and the Internet of Things. The analog-to-digital converter (ADC), as a medium connecting the analog world and the digital world, directly determines the performance of the entire system to a certain extent. In the information age, ADCs are widely used in wireless communication, high-speed data acquisition, industrial control, instrumentation measurement, audio and video digitization and other fields. Driven by the market and applications, people have put forward higher requirements for the compromise des...

AI Technical Summary

Problems solved by technology

In the sampling structure of the lower plate, the input voltage is only passed through the switch, which is less affected by parasitics, but the number of required unit capacitances will double that of the sampling structure of the upper plate, thus limiting the speed of the SAR ADC;

[0006] 3) In order to reduce the area of ​​the capacitor array, the researchers proposed a segmented capacitor array on the basis of the traditional binary capacitor array. The binary relationship between the capacitor arrays is still satisfied, and the capacitance value of the required bridge capacitor is fractional, which greatly increases the difficulty of circuit design, and also puts forward very high requirements for layout matching;

[0007] 4) In the switching sequence, the researchers proposed the monotonic switching sequence and the switching sequence based on the common mode level, both of which can effectively reduce the energy consumption compared with the traditional switching sequence, and the switching sequence based on the common mode level The energy efficiency is optimal, but the complexity of the circuit based on the common-mode level switching scheme is increased, which increases circuit resources and requires more precise control circuits in terms of timing

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