How do I increase the resolution of ADC?

How do I increase the resolution of ADC?

The accuracy of a low-resolution ADC can be improved by oversampling the input signal using the ADC and subjecting it to low-pass filtering, using a FIR filter to filter out the quantization noise, and then decimating it.

What is the effect of oversampling?

Oversampling is capable of improving resolution and signal-to-noise ratio, and can be helpful in avoiding aliasing and phase distortion by relaxing anti-aliasing filter performance requirements. A signal is said to be oversampled by a factor of N if it is sampled at N times the Nyquist rate.

What is oversampling ADC?

To increase the effective number of bits (ENOB), the signal is oversampled, or sampled by the ADC at a rate that is higher than the system’s required sampling rate, fs.

How the accuracy of ADC can be improved?

To minimize the ADC errors related to the external environment, take care of the reference voltage and power supply, eliminate the analog-input signal noise, match the ADC dynamic range to the maximum signal amplitude, and match analog-source resistance.

What is oversampling and decimation?

Basically, the input signal is oversampled. Oversampling means that samples are taken at a much higher rate than the sampling frequency. Decimation drops samples while interpolating the samples in-between each sample period through a low pass filter.

Does oversampling improve accuracy?

You won’t necessarily increase the accuracy of a measurement by oversampling. Any systematic errors and uncertainty will remain.

What is oversampling and undersampling in ADC?

The ADCs for these systems must have wide signal bandwidths but do not need high maximum clock frequencies. As we saw in an earlier RAQ2 it is possible to improve the resolution of a sampled data system by increasing the sampling clock rate–the procedure is known as oversampling.

When or why should we use oversampling?

Oversampling and undersampling in data analysis are techniques used to adjust the class distribution of a data set (i.e. the ratio between the different classes/categories represented). These terms are used both in statistical sampling, survey design methodology and in machine learning.

Why higher ADC resolution could provide better conversion accuracy?

Higher resolution correlates to a slower conversion rate. The accuracy of a converter refers to how many bits, from conversion to conversion, are repeatable. That is, accuracy reflects how true the ADC’s output reflects the actual input. The ADC still has a resolution as advertised, but accuracy suffers with the LSBs.

What does the resolution of ADC imply?

The resolution of the ADC is the number of bits it uses to digitize the input samples. Thus, a 12 bit digitizer can resolve 212 or 4096 levels. The least significant bit (lsb) represents the smallest interval that can be detected and in the case of a 12 bit digitizer is 1/4096 or 2.4 x 10-4.

How the resolution of an ADC depends on?

The number of binary digits (bits) that represents the digital number determines the ADC resolution. However, the digital number is only an approximation of the true value of the analog voltage at a particular instant because the voltage can only be represented (digitally) in discrete steps.

How much does oversampling increase dynamic range?

As a general guideline, oversampling the ADC by a factor of four provides one additional bit of resolution, or a 6 dB increase in dynamic range. Increasing the oversampling ratio (OSR) results in overall reduced noise and the DR improvement due to oversampling is ΔDR = 10log10 (OSR) in dB.

What are the advantages of oversampling a SAR ADC?

Besides oversampling with a Δ-Σ ADC, oversampling a high throughput SAR ADC can improve antialiasing and reduce overall noise. In many cases, oversampling is inherently used and implemented well in Δ-Σ ADCs with an integrated digital filter and decimation functionality.

How can I increase the resolution of analog-to-digital (ADC) measurements?

Oversampling and averaging can increase the resolution of a measurement without resorting to the cost and complexity of using expensive off-chip ADCs. This application note discusses how to increase the resolution of analog-to-digital (ADC) measure- ments by oversampling and averaging.

How does oversampling improve noise reduction?

Increasing the oversampling ratio (OSR) results in overall reduced noise and the DR improvement due to oversampling is ΔDR = 10log10 (OSR) in dB. Besides oversampling with a Δ-Σ ADC, oversampling a high throughput SAR ADC can improve antialiasing and reduce overall noise.