Sigma-Delta Analog-to-Digital Converter is a kind of analog-to-digital converter, which is a kind of equipment used to convert continuous signals in analog form into discrete signals in digital form. An analog-to-digital converter can provide a measurement signal. The opposite device becomes a digital-to-analog converter.

In the automatic control system, the controlled or measured objects are mostly changing physical quantities, and this continuous changing physical quantity refers to the continuous changing quantity in time and value, which is what we often call physical quantities. The value and polarity of the analog quantity are measured by the sensor. When using single chip microcomputer to participate in the measurement, they must be converted into digital quantities to be accepted by single chip microcomputer.

Extended data

The main performance indicators of Sigma-Delta ADC are: dynamic range (DR), signal-to-noise ratio (SNR), signal-to-noise distortion ratio (SNDR), effective number of bits (ENOB) and overload (OL). That is, in, the vertical axis is SNR or SNDR, both of which are expressed in dB.

When the input signal amplitude is small, the signal-to-noise ratio and SNDR are equal; With the increase of input amplitude, distortion will reduce the performance of the modulator, so when the input amplitude is large, SNDR will be less than SNR.

Oversampling ADC or noise shaping ADC is also called Delta-Sigma ADC. Many names. The modulator is basically composed of a difference channel and an integral-sum circuit, and then the digital output of Nbit is obtained through a digital filter.

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