ADS131A04EVM: do we need to buffer the input signal before connecting to the ADC pins

anand Chandrasekhar

Part Number: ADS131A04EVM

In the ADS131A04EVM board, do we need to buffer the signal before connecting to the ADC pins ?

My sensor is a simple wheastone bridge). Without EVM, sensor outputs 4 mV. When EVM is connected, the output is changing to 9mV

Does the ADC has an internal Buffer to prevent loading ?

Regards,

0 Tom Hendrick over 7 years ago

Hi anand,

The input to CH1 (AIN1P and AIN1N) provides an option to buffer your signal. That input is on J6 of the ADS131A04EVM, pins 1 and 3.

0 anand Chandrasekhar over 7 years ago in reply to Tom Hendrick

Thank you. Ch1 = J6, Ch2 = J7, Ch3 = J9, Ch4 = J10.
Is this right that J6 and J10 are buffered ?

0 Tom Hendrick over 7 years ago in reply to anand Chandrasekhar

J10 is buffered, but that is a single ended setup. Try using J6 and let us know if you see any difference.

0 anand Chandrasekhar over 7 years ago in reply to Tom Hendrick

J6 still loads the sensor . I think we need an external buffer .

0 anand Chandrasekhar over 7 years ago in reply to anand Chandrasekhar

I forgot to Toggle switch s5 to Buffer Mode... thank you very much

0 Tom Hendrick over 7 years ago in reply to anand Chandrasekhar

Great! Thanks for letting us know!

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