What is the effective resolution from 24-Bit A/D Converter?

Leonardo Rocha

Other Parts Discussed in Thread: MSP430AFE251

Hi,

Please, I would like to know more information about effective resolution from MSP430AFE251's A/D Converter. I cant find this information with details at following links:

http://www.ti.com/lit/ug/slau144j/slau144j.pdf

http://www.ti.com/lit/ds/symlink/msp430afe251.pdf

Best regards!

Leo

over 12 years ago

0 Jason Work over 12 years ago

TI__Genius 10830 points

How much of the information you are looking for is in this forum thread?

MSP430F6726 24 bit sigma-delta ADC question

0 Tyler Andrews over 12 years ago in reply to Jason Work

Prodigy 190 points

24-bit would be equal to 2^24 = 16777216.

0 Ilmars over 12 years ago in reply to Tyler Andrews

Guru 46710 points

Tyler Andrews said:
24-bit would be equal to 2^24 = 16777216.

Tyler, what do you mean answering something like this?

0 Tyler Andrews over 12 years ago in reply to Ilmars

Prodigy 190 points

As I understood the question, Leonardo was trying to figure out what the resolution(or how sensitive) of his 24-bit ADC is and hence its maximum value. Now that I look at the question again it is apparent that he actually wrote A/D not ADC. My bad.

Tyler

0 Ilmars over 12 years ago in reply to Tyler Andrews

Guru 46710 points

Tyler Andrews said:
he actually wrote A/D not ADC. My bad.

He wrote "A/D converter" which is essentially the same as to say "ADC". Asking for effective resolution of delta-sigma A/D converter (ADC) is quite right question because they differ. So, what's effective resolution of MSP430AFE251 24-bit A/D Converter?

0 Jens-Michael Gross over 12 years ago in reply to Ilmars

Guru 227245 points

Ilmars said:
So, what's effective resolution of MSP430AFE251 24-bit A/D Converter?

At first glance, this should be Vref/(2^24). But this would be naive fallacy.
Teh datasheet tells the SNR which limites the useful bits of the conversion results and therefore the effective resolution. Also the selected oversampling ratio and the selected gain have an effect. So there is no general one-value answer to this question.

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What is the effective resolution from 24-Bit A/D Converter?