Adaptive alternating successive approximation analog-to-digital converter with low power consumption, and control method

Abstract

The invention provides an adaptive alternating successive approximation analog-to-digital converter with low power consumption, comprising a comparator, capacitor arrays and a control logic circuit, wherein a positive input end of the comparator is connected with a forward capacitor array, and a negative input end of the comparator is connected with a reverse capacitor array; an output end of thecomparator is connected with the control logic circuit; an upper polar plate of the forward capacitor array is connected with a positive input voltage, and a lower polar plate of the forward capacitorarray is respectively connected to a reference voltage and is grounded through a forward selection switch; the upper polar plate of the reverse capacitor array is connected with a negative input voltage, and the lower polar plate of the reverse capacitor array is respectively connected to the reference voltage and is grounded through a reverse selection switch; and the forward selection switch and the reverse selection switch are both connected with the control logic circuit. The invention also provides a corresponding control method. The adaptive alternating successive approximation analog-to-digital converter with low power consumption provided by the invention has the advantages that the design difficulty of the digital logic circuit can be reduced and the overall power consumption canbe reduced.

Description

technical field [0001] The invention relates to an analog-to-digital converter, in particular to a low-power self-adaptive alternating successive approximation analog-to-digital converter and a control method. Background technique [0002] Analog signals such as biomedical electrical signals and sensor detection signals tend to have small fluctuations in amplitude over a long period of time. When converting analog signals, traditional successive approximation analog-to-digital converters use the dichotomy method for testing, that is, first predict the range of the input signal, and then continuously narrow the range to finally obtain the digital code. The disadvantage of this method is that even if the amplitude of the input signal is very small most of the time, each conversion still needs to start from the maximum interval to predict, and then gradually narrow the range of the interval, which will inevitably generate a lot of unnecessary Switching power consumption, compa...

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Problems solved by technology

The disadvantage of this method is that even if the amplitude of the input signal is very small most of the time, each conversion still needs to start from the maximum interval to predict, and then gradually narrow the range of the interval, which will inevitably generate a lot of unnecessary Switching power consumption, comparative power consumption, and power consumption of the digital control section

However, this algorithm has the following defects: 1. It needs to use more registers to store the digital code obtained last time, which will increase the area and power consumption; 2. The quantization step of judgment is increased, which is equal to increased power consumption; 3. It must be required that the amplitude changes of the two sampling points before and after are very small, otherwise the power consumption will increase

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