ADS1198 in AC coupling approach

Alicia Beatriz

Other Parts Discussed in Thread: ADS1198, ADS1298

I'm trying to use the ADS1198 in AC coupling approach, because I need best resolution (with gain of 6 I have 12.2uV of LSB and I want 6.1uV).
Someone could show me a schematic showing this setting to take a 12-lead ECG, (RA, LL, LA, and V1 to V6)
Thank you very much

over 9 years ago

0 Brian Pisani over 9 years ago

TI__Mastermind 38745 points

Hey Alicia,

You can half the LSB size by doubling the PGA gain from 6 to 12. Besides this, you could use the ADS1298 which has 24 bits of resolution. An example of AC coupling can be found in the ADS1298 datasheet in Figure 95. The negative inputs of the channels connected to Vx leads are typically connected to the WCT output. An example of this can be found in the ADS1198 EVM schematic.

Regards,
Brian Pisani

0 Alicia Beatriz over 9 years ago in reply to Brian Pisani

Prodigy 115 points

Hi Brian, thank you for your responce!!

If I use a AC coupling approach with the ADS1298, There is any example from TI to show how can implement a FIR filter (or anoder filter type) with low delay in the response?.

I'm studying how to make a filter that is no more than 500ms of delay in response with a sampling frequency of 500Hz and I can not make a FIR high pass with less than 4000 coefficients, with a cut in 0.05Hz.

IEC requests that specification for an ECG that will be useful for measurements in the ST segment.

I look forward to hearing from you :)

Regards

0 Brian Pisani over 9 years ago in reply to Alicia Beatriz

TI__Mastermind 38745 points

Hello Alicia,

If you ac couple the inputs, why would you then need a digital HPF? Perhaps I did not understand your application well enough.

Brian

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ADS1198 in AC coupling approach