Methods to increase noise immunity in adc

[arsen55591]

How to increase noise immunity in adc

 

[barry]

1) Good PCB layout
2) Low noise components
3) Filtering

 

[shaiko]

1.If the sampled signal is DC - use a capacitor in parallel to the line - very close to the ADC's input.

2. Don't drive your sampled signal directly to the ADC - instead, use a unity gain amplifier (analog buffer) with a very high input impedance.

3. Keep the length of your traces as short as possible and route them adjacent to ground or power planes.

4. Use a differential ADC

 

[ads-ee]

TI has a lot of white papers on this type of subject here is a nice seminar paper on PCB layout for high resolution ADCs.

https://www.ti.com/lit/ml/slyp167/slyp167.pdf

 

[arsen55591]

It is possible use additional feadback to increase noise immunity, for example in pipeline ADC's MDAC we have feadback in phase of sampling but don't have feadback in phase of multiphlication. If we don't cut feadback in phase of multiphlication can it help me to increase noise immunity.

 

[darkgnat]

You can also use averaging and/or digital filtering on the chip in addition to any external analog filtering. Note with digital filtering you will want an external low pass filter with a bandwidth no wider than half your expected highest desired spectral component or you will end up with aliasing in any digital filtering you use.

 

[D.A.(Tony)Stewart]

A better description of noise will give you a better answer.

 

[Shanmukesh]

A low values capacitor (Say 0.01uF) will help the purpose. Moreover, Care should be taken that the cap is as close to the ADC as possible else it will result in formation of a trace loop antenna which will degrade EMC/EMI performance further.

Several times a smd choke (10uH, 0805) on the ADC trace improves the results dramatically.