Multi-input analog-to-digital converter capable of resampling

Abstract

The invention belongs to the technical field of data quantization processing in an integrated circuit, and discloses a multi-input analog-to-digital converter capable of resampling. The converter comprises digital-to-analog converters, a selection switch array, a comparator, a digital control circuit and a group of resampling switches connected with a positive end and a negative end of the comparator, wherein the digital-to-analog converters adopt capacitive digital-to-analog converters, are divided into N groups and are used for simultaneously sampling N groups of input signals in quantization processing; the comparator is used for sequentially comparing the quantized difference values of the N groups of quantized input signals; the digital control circuit is connected to an output end ofthe comparator and executes resampling reset of the comparator by controlling the resampling switch to be switched on; in conclusion, the positive end voltage and the negative end voltage of the comparator can be reset to the common-mode voltage before the comparator performs comparison each time, so the residual voltage generated in multiple comparison processes is effectively eliminated, and the quantization precision of the whole analog-to-digital converter is further improved.

Description

technical field [0001] The invention belongs to the technical field of data quantization processing in integrated circuits, and in particular relates to a resampling multi-input analog-to-digital converter. Background technique [0002] Data quantization is to convert an analog signal into a digital signal, and a circuit that converts an analog signal to a digital signal is called an analog-to-digital converter. There are many types of existing analog-to-digital converters, mainly including pipeline-structured A / D converters, successive approximation analog-to-digital converters (SAR ADCs), oversampling analog-to-digital converters, and the like. Specifically, when the analog-to-digital converter performs analog-to-digital conversion, it needs to quantize multiple sets of input analog signals. [0003] At present, in order to realize the simultaneous quantization of multiple sets of input analog signals, a patent (202010399223.5) proposes an analog-to-digital converter for ...

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Problems solved by technology

[0003] At present, in order to realize the simultaneous quantization of multiple sets of input analog signals, a patent (202010399223.5) proposes an analog-to-digital converter for quantizing multiple sets of inputs. A digital-to-analog converter array (DAC) is embedded in the converter. When sampling and quantizing multiple sets of input signals, the digital-to-analog converter array is used to simultaneously sample multiple sets of signals, and then convert them in turn, which is equivalent to multiple sets of signals being sampled and converted at the same time; High problem, the reason is:

[0004] to combine Figure 1-Figure 2 It can be seen from the schematic diagram of the structure that at the beginning of quantization of the first group of input signals, the initial value of the voltage at the input terminal of the comparator is a common-mode voltage, and during the quantization process, the voltage at the input terminal of the comparator keeps changing; when the first group of input signals After the signal quantization is completed, according to the characteristics of the successive approximation analog-to-digital converter, there is a residual voltage at the input terminal of the comparator, and the range of the residual voltage value is 1 minimum weight voltage (LSB); the above residual voltage causes the voltage at the input terminal of the comparator to fail. Return to the initial value of the common-mode voltage, thus affecting the accuracy of the group of input signals when the second group of input signals are quantized, and so on, which will affect the accuracy of the final quantization result of the group of analog-to-digital converters

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