ADS131M06: ADC Noise measurement to achieve resolution

Deepak c

Prodigy 100 points

Part Number: ADS131M06

Hi,

Can you please help me in understanding noise level lost in conversions?

I wanted to measure 300VAC with the resolution of 1V

how i will make sure that with this ADC, I will achieve this resolution.

Regards,

Deepak

over 5 years ago

0 Ryan Andrews over 5 years ago

TI__Guru 68326 points

Hello Deepak,

Thank you for your post and welcome to our forum.

1V / 300 Vac is approximately 50 dB of dynamic range: 20 x log10 (1 / 300). With the ADS131M06, you can achieve up to 102 dB at Gain = 1, or up to 80 dB at Gain = 64. Your input signal will have to be divided down to within the full-scale and absolute voltage ranges of the ADS131M06.

Regards,

Ryan

0 Deepak c over 5 years ago in reply to Ryan Andrews

Prodigy 100 points

Hi Ryan,

Thanks for answer.

How we can validate?

How data can be processed?

I have seen some of the noise floor level measurement?

0 Deepak c over 5 years ago in reply to Ryan Andrews

Prodigy 100 points

Well,

Just to correct below

20xlog(1/300)= (-)50 dB not 50dB

0 Ryan Andrews over 5 years ago in reply to Deepak c

TI__Guru 68326 points

Of course, technically then it is 20*log(300/1). We generally speak of dynamic range in absolute terms to describe the difference between two magnitudes: the largest and smallest signals measured by the system.

You can validate the noise performance of the device by shorting the input pins together and biasing them to a mid-supply common-mode. The results of the peak-to-peak and RMS noise that you measure will be very close to the data presented in the Noise Measurements table in the data sheet.

Regards,

0 Deepak c over 5 years ago in reply to Ryan Andrews

Prodigy 100 points

Hi Ryan,

Got it..

I have designed circuit already with with 91k (Upper) and 1k (bottom)

Now i wanted to measure noise floor with the data that i have processed via UART.

How i will come to conclusion that we are achieving resolution of 1V

0 Ryan Andrews over 5 years ago in reply to Deepak c

TI__Guru 68326 points

Hi Deepak,

A change of 1 V in your input signal will produce a change of 10.9 mV at the ADC input using the resistor divider circuit you described. This is much better than the resolution of the ADS131M06.

Regards,

Ryan

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ADS131M06: ADC Noise measurement to achieve resolution