Remove DC Offset from ADS1298

Ahmed Qureshi41

Prodigy 115 points

Part Number: ADS1298ECGFE-PDK

please also tell me how to remove dc offset which is about +/-300v.

over 8 years ago

0 Ryan Andrews over 8 years ago

TI__Guru 68916 points

Hi Ahmed,

DC offset voltage is expected due to large, imbalanced electrode impedance and also the input bias/lead-off detection current. IEC standards require that you can still measure the ECG signal amplitude in the presence of +/-300mV electrode offset voltage. You can either use the RLD to establish a mid-supply common-mode and reduce the differential signal gain, or you can AC-couple the electrode inputs.

Best Regards,

0 Ahmed Qureshi41 over 8 years ago in reply to Ryan Andrews

Prodigy 115 points

thanks, it mean that we should not need any kind of circuit to remove dc off set

0 Ryan Andrews over 8 years ago in reply to Ahmed Qureshi41

TI__Guru 68916 points

Not unless the ADC output is saturating and you cannot reduce the gain any further.

Regards,

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Remove DC Offset from ADS1298