ADS1278: Single ended drive into inputs.

Leo A.

Part Number: ADS1278

Hello,

The datasheet hast the info below. My question is how do I properly drive the AINP input if I have AINN connected to a reference voltage of 2.5V (See below)? To get the full converter range do I drive AINP from 0 to 5V or am I limited to driving 0 to 2.5V it is not made very clear.

Thanks;

Leo

over 3 years ago

0 Leo A. over 3 years ago

Intellectual 515 points

I am not sure why images are not showing up in the first post here they are:

0 Keith Nicholas over 3 years ago in reply to Leo A.

TI__Mastermind 36170 points

Hello Leo,

Yes, you can drive AINNx inputs with the nominal reference voltage of 2.5V. The AINPx input can then swing from 0V to 5V, resulting in a differential input voltage range of +/-2.5V.

In this case, You will get the following conversion codes:

AINPx=0V, the conversion code will be negative full scale, or -2^23 decimal.

AINPx=2.5V, the conversion code will be 0 decimal

AINPx=5V, the conversion code will be positive full scale, or 2^23-1 decimal.

Regards,
Keith Nicholas
Precision ADC Applications

0 Leo A. over 3 years ago in reply to Keith Nicholas

Intellectual 515 points

Perfect, thank you.

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ADS1278: Single ended drive into inputs.