Adaptive digital techniques to suppress quantization noise of ΣΔ analog to digital converters

High performance adaptive sensor interface design through model based estimation of analog non-idealities

“…The ANC is placed at the end of the ΣΔ ADC ( Fig.1) and in this way all of necessary signal processing is done in software and no complexity is added to the modulator itself. This is totally different to the technique discussed in [9], [10] where it is being done in digital domain and before decimation. To realize the ANC, an adaptive FIR filter based upon [11] method is used.…”

“…With this technique, errors introduced by non-idealities in analog circuits are removed in the digital domain [9]. Digital correction methods correct these errors by having information hidden in digital output.…”

“…Adaptive correction of the ADC output in the micro-controller shows a significant improvement of signal quality leading to the noise ground correction which is natural with adaptive filtration. The uniform nature of the noise, input to adaptive correction algorithm also corrects signal non-linearities due to analog blocks [9], which has been exploited here to improve the signal quality. This implementation of adaptive correction technique in micro-controller is novel in comparison to State-of-Art techniques where the adaptive components were used within the analog or in the DSP making it complex to realize.…”

Suppression of delta-sigma DAC quantisation noise by bandwidth adaptation

“…The synthesiser uses a programmable bandpass ∆Σ modulator and adjusts the notch frequency of the noise shaping function to suit the synthesised signal. In [8], active noise cancellation techniques are used to reduce quantisation noise. When applied to an A/D converter, an adaptive line enhancer (ALE) is used to provide adaptive filtering of the digital modulator output-providing the best estimate of the signal in the mean squared sense, provided that the noise is wideband compared to the signal and uncorrelated.…”