ADS1293: Question of ADS1293 Lead-Off Without RL

Wayne Chen (Audio AE)

Part Number: ADS1293

Hi Sirs,

My customer can bring up the ADS1293 and capture ECG waveforms. The lead-off function works with RA LA LL and RL connected, but malfunction with no RL.
Would you please advise the hardware and software configurations to enable the lead-off function with RA LA LL with no RL connection?

Thank you and Best regards,

Wayne Chen
08/10/2019

over 6 years ago

0 Alexander Smith over 6 years ago

TI__Guru 55342 points

Hi Wayne,

More than likely the customer needs a way to bias the inputs of the device. The RL connection is ensuring that the measurement is within the common-mode range of the PGA and without this RL connection the measurement drifts out of the common-mode range.

Take a look at my picture and explanation from this post: https://e2e.ti.com/support/data-converters/f/73/t/799662

A configuration like this may solve the issue.

Data converters

Data converters forum

ADS1293: Question of ADS1293 Lead-Off Without RL