Hi,

I have an query related to ADC selection for the higher channel bandwidth signal.

How to select the ADC for the higher channel bandwidth signal?

what are the parameters have to see for the same?

Thanks in advance....

Hi,

I have an query related to ADC selection for the higher channel bandwidth signal.

How to select the ADC for the higher channel bandwidth signal?

what are the parameters have to see for the same?

Thanks in advance....

Hi,

Theoretically, an ADC can process a signal bandwidth that is ½ of the sample rate (f

_{s}). However, in almost all applications the useable bandwidth is lower than ½ the sample rate because of the need for an anti-aliasing filter upstream from the ADC. A good rule of thumb is that the ratio of sample rate to bandwidth of interest should be at least 6 to realize a reasonable filter complexity. Some designs choose to over sample by 10 or 20 times the bandwidth of interest to simplify the anti-aliasing filter. The other big factor in choosing the sample rate in your design is determining the noise at the output of the ADC. The noise spectral density at the output of the ADC is determined by several factors, but first order it is driven by the quantization and thermal noise of the ADC. This noise is ideally spread out evenly over the ADC’s output bandwidth (f_{s}/2). So higher oversampling ratios also spread out the noise over a bandwidth which is much wider than the signal of interest, thereby improving the signal to noise ratio. Obviously, there are tradeoffs. Higher oversampling ratios require more signal processing, burn more power, and cost more. If you need a refresher on the fundamentals of ADCs, a good place to start is an online seminar on ADCs:Regards,

David

Hi,

Theoretically, an ADC can process a signal bandwidth that is ½ of the sample rate (f

_{s}). However, in almost all applications the useable bandwidth is lower than ½ the sample rate because of the need for an anti-aliasing filter upstream from the ADC. A good rule of thumb is that the ratio of sample rate to bandwidth of interest should be at least 6 to realize a reasonable filter complexity. Some designs choose to over sample by 10 or 20 times the bandwidth of interest to simplify the anti-aliasing filter. The other big factor in choosing the sample rate in your design is determining the noise at the output of the ADC. The noise spectral density at the output of the ADC is determined by several factors, but first order it is driven by the quantization and thermal noise of the ADC. This noise is ideally spread out evenly over the ADC’s output bandwidth (f_{s}/2). So higher oversampling ratios also spread out the noise over a bandwidth which is much wider than the signal of interest, thereby improving the signal to noise ratio. Obviously, there are tradeoffs. Higher oversampling ratios require more signal processing, burn more power, and cost more. If you need a refresher on the fundamentals of ADCs, a good place to start is an online seminar on ADCs:http://www.analog.com/library/analogDialogue/archives/39-06/Chapter%202%20Sampled%20Data%20Systems%20F.pdf

Regards,

David