ADS7951-Q1: ADC acquisition accuracy and calibration method

user5821545

Part Number: ADS7951-Q1
Other Parts Discussed in Thread: ADS1148

At present, I have a design idea to collect high voltage (100-800V) by means of resistance partial voltage;

I need the acquisition accuracy of the final system at 0.5%, each of the sample values, full temperature range(-40~85℃);

However, I am considering whether the 12-bit ADC can meet the requirements and whether there are relevant calculation methods for the true error of ADC；

At present, the errors I can identify come from the following aspects: ADC error, REF error, and the partial pressure resistance error；

Or is there any relevant calibration method for reference？

I think the price of a 12-bit ADC is cheap, therefore, should I obtain higher accuracy through calibration or choose a higher accuracy ADC(such as ADS1148)?

If you have good Suggestions, please help me choose;

over 3 years ago

0 Cynthia over 3 years ago

TI__Mastermind 24940 points

Hello,

There is an excellent blog on the total unadjusted error of an ADC that I believe will be very helpful for what you are trying to do. This will provide great background information and provide clear direction for moving forward

ADC Accuracy Part 2: Total Unadjusted Error Explained, notes that this is part 2 of a three part blog. I would suggest taking a look at the rest as well.

Regards

Cynthia

0 user5821545 over 3 years ago in reply to Cynthia

Prodigy 30 points

Thanks for your reply. I think I understand the total error of ADC；

I would like to know if there is any method of ADC system calibration for reference？

0 Cynthia over 3 years ago in reply to user5821545

TI__Mastermind 24940 points

There is a 2 point calibration method. We do not a document that explicitly explains this, but is included within documentation

I would suggest looking at

Reducing effects of external RC filter circuit on gain and drift error for integrated analog front ends (AFEs): ±10V, on page 5, the calibration method and benefits is covered. Note that this document used a different device as an example, but the method would be applied the same

for shorter coverage on this, there is Circuit to increase input range on an integrated analog front end (AFE) SAR ADC, on page 3

Regards

Cynthia

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ADS7951-Q1: ADC acquisition accuracy and calibration method