ADC input from low pass filter

[abhishek.2138]

Hello,
I am using 10 bit ADC with Vref = 5V, want to interface with analog circuit.
What should be my input low pass filter cut off frequency?

 

[andre_luis]

What should be my input low pass filter cut off frequency

What about mentioning sample rate ?
Input signal frequency/bandwidth, etc...

 

[danadakk]

Front end design :

https://www.analog.com/en/analog-dialogue/articles/practical-filter-design-precision-adcs.html

And some interesting links and references in it.

Some excellent comments on what Nyquist did not say :

https://www.wescottdesign.com/articles/Sampling/sampling.pdf

Good ref handbook :

The Data Conversion Handbook, 2005 | Education | Analog Devices​

The Data Conversion Handbook, Edited by Walt Kester, Newnes, 2005, ISBN 0-7506-7841-0. Also published as Analog-Digital Conversion, Analog Devices, Inc. 2004, ISBN 0-916550-27-3.The Data Conversion Handbook is written for design engineers who routinely use data converters and related circuitry...
www.analog.com


Regards, Dana.

 

[abhishek.2138]

What about mentioning sample rate ?
Input signal frequency/bandwidth, etc...

HI,
Andre_Luis,

The sample rate = 30KHz (30 MSPS) &
Bandwidth = 1 KHz, frequency = 10KHz

Can you pls let me know how to design RC to interface ADC.
Is it filter cut off freq. > max input freq.?

 

[danadakk]

https://e2e.ti.com/blogs_/archives/b/precisionhub/posts/three-guidelines-for-designing-anti-aliasing-filters

Guide to Anti-aliasing Filter Basics | Maxim Integrated

Learn about Filter Basics for Anti-Aliasing and the types of filters that can be used for anti-aliasing. Find info on Anti-Aliasing today.

www.maximintegrated.com

https://www.edn.com/designing-antialias-filters-for-adcs/

The above might help.


Regards, Dana.

 

[barry]

HI,
Andre_Luis,

The sample rate = 30KHz (30 MSPS) &
Bandwidth = 1 KHz, frequency = 10KHz

Can you pls let me know how to design RC to interface ADC.
Is it filter cut off freq. > max input freq.?

Well, is it 30 kHz or 30 MHz??

You're on the right track. Yes, the filter cutoff should obviously be higher than your frequency of interest. But you still need to know some other factors, like how much out-of-band attenuation do you need? If it is, in fact, 30 MHz sample rate you could use a 1MHz cutoff. Or 20kHz.