ADS1220: How to use to +/-%V analog signal?

Sridhar M S

Part Number: ADS1220

In my application, I want to measure +/-5V analog signal. We have designed and developed the board with ADS1220 for analog siganl measurment. We are facing problem when we are measuring the negative -5V analog signal. ADC measures well up to -0.3VDC then measurement drops.

RefP0 was connected +2.5V and RefN0 was connected to -2.5VDC.

Do you have reference design for bipolar measurement?

Is there any settings missed by us?

over 7 years ago

0 Bob Benjamin over 7 years ago

TI__Guru** 113765 points

Hi Shridhar,

I mostly explained this in your other question you posted:

https://e2e.ti.com/support/data_converters/precision_data_converters/f/73/p/715777/2640561#2640561

We don't have a specific reference design as this is fairly straightforward. The only real considerations are that you must not apply an input greater than the supply rails, and bipolar input signals require bipolar analog supplies. This is discussed in the ADS1220 datasheet on page 47 in the Application Information third paragraph from the top of the page.

Best regards,

Bob B

0 Sridhar M S over 7 years ago in reply to Bob Benjamin

Prodigy 70 points

Thank you for your reply. I tested the ads1220 as suggested by you. But there was no success. ADC value measured in AI0 saturated to 2.0V. the setup details are posted in the other post that you referred in your response.

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ADS1220: How to use to +/-%V analog signal?