Successive approximation analog-digital converter structure and low-power-consumption switching method thereof

Abstract

The invention discloses a successive approximation analog-digital converter structure and a low-power-consumption switch method thereof. Compared with a conventional full base plate sampling technology, the successive approximation analog-digital converter structure has the advantages that only one pair of bootstrapped sampling switches is needed by a highest-order capacitor bottom plate sampling technology, so that the accuracy of a successive approximation analog-digital converter is increased; the switching area is reduced; and the power consumption is lowered. Through adoption of the switching method provided by the invention, energy is not consumed during generation of first two orders in a switching process. Moreover, only a common-mode voltage V<cm>=(1/2)V<ref> is taken as a reference voltage, so that dynamic energy consumption in the switching process is lowered greatly. Redundant bit capacitors are introduced into conversion of a capacitor array digital-analog converter, so that the total area of the capacitors is reduced greatly, and the switching energy consumption is further lowered. The successive approximation analog-digital converter structure is suitable for a high-accuracy low-power-consumption successive approximation analog-digital converter, and has a very good economic benefit.

Description

technical field [0001] The invention relates to a successive approximation analog-to-digital converter structure and a low-power switching method using the highest-bit capacitor bottom plate sampling technology, and belongs to the technical field of analog-digital hybrid integrated circuits. Background technique [0002] Successive approximation analog-to-digital converter (SAR ADC) is a medium-to-high-precision and medium-speed analog-to-digital converter. It is a non-op-amp structure with the advantages of low power consumption and small area. It is often used in mobile devices, Applications such as handheld medical diagnostic equipment and wireless sensors. Capacitor array digital-to-analog converter is a key module in SAR ADC, and its energy consumption in the conversion process occupies a large proportion in the entire SAR ADC. In the traditional structure, the capacitors in the capacitor array DAC occupy a large area, resulting in huge energy consumption during the sw...

AI Technical Summary

Problems solved by technology

In order to ensure better linearity and rail-to-rail input range, gate voltage bootstrap sampling switches are generally used. The disadvantage is that in the traditional structure, N-bit precision needs to use 2N grid voltage bootstrap sampling switches, which brings a lot of problems. Large power consumption and area overhead

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