Other Parts Discussed in Thread: ADS1296, ADS1294, ADS1292, ADS1293, ADS1291, ADS1278, ADS1298, , ADS1198, ADS1258, TLV4333, ADS131E08,
I an designing a low cost 12 lead ECG machine . For that option from TI is ADS 1298 , ADS 1198 ,ADS 1258 , ADS1278 (8 DIFF CHANEL) , ADS1293( 3 nos) and ADS1292,ADS1291, ADS1294 , ADS1296 ( 1,2,4,6) Channel.
ADS1298 , ADS1258, ADS 1278 are expensive and ADS1198 is 16 bits resolution & other multiple combination of 1,2,3 , 4 channel A/D alo proves costly. One option is to us low cost ADS131M08 for ecg purpose. Same question you have answered as follow 3 years back
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That being said, my concern with choosing the ADS131M08 is the low input impedance. ECG applications are usually challenged by large skin-to-electrode contact impedance. You want the input impedance of the ADC to be very high in order to preserve the signal amplitude and to minimize leakage currents.
They would need an external buffer with high input impedance in front of the ADS131M08. For ECG applications, I don't think this is the right approach as it may lead to CMRR degradation.
Has the customer considered some of our dedicated bio potential front-end ADCs like the ADS1298?
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But what if I choose a op-amp buffer like TLV4333IDR for buffering input (unit gain buffer) ecg electrodes before ADS131M08.
TLV4333 - input impedance 10 G ohms
CMRR = 110-125 d
input offset < 30 uv
Gain−Bandwidth 350 kHz (
Low Offset Drift: 0.07 V/°C
Please advice
