ADS1298: ECG input protection diodes

Maciej Lasota

Part Number: ADS1298

Hello,

Does anybody know what type of input protection diodes should be used in real-life ECG application? (picture from ADS1298RECGFE-PDK below as a reference)

I have tried with Schottky diodes, but I noticed some problems with lead-off detection. Not connected electrodes were detected as connected, probably because significant leakage current. So I guess that Schottky is not the best choice. What type of diodes should be used to have enough protection, but no problem with leakage current?

Thanks & regards
Maciej

over 4 years ago

0 Alexander Smith over 4 years ago

TI__Mastermind 47625 points

Hi Maciej,

I would say that it varies from application to application depending on requirements. You may need to consider using a TVS diode and/or adjusting some components to make the Schottky diodes work properly.

This video series should help: https://training.ti.com/eos-and-esd-adc?context=1139747-1140267-1128375-1139109-1137697

0 Maciej Lasota over 4 years ago in reply to Alexander Smith

Prodigy 170 points

Hi Alex,

Thank you for information. I will have a look on the video.

Do you know if there is any application note describing protection of ECG inputs and it's impact on lead-off detection?

Best regards
Maciej

0 Alexander Smith over 4 years ago in reply to Maciej Lasota

TI__Mastermind 47625 points

Hi Maciej,

Not that I know of unfortunately. The video series is pretty comprehensive, mostly working with SAR converters but most of the theory applies to delta-sigma converters as well.

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ADS1298: ECG input protection diodes