The circuit shown in Figure 1 is optimized for high resolution (18 bits) and ultra low power for wearable and portable medical applications. The passive filtering and compensation network is optimized for noise reduction, charge kickback reduction, and stability.
Figure 1: Ultra Low Power Data Acquisition Block for Medical Applications
To configure your input source (this can be a medical sensor, ECG signal, or transducer output) use the signal editor in SPICE (TINA) and select “piecewise linear” signal and paste your signal from a spread sheet into the editor as shown below:
To see an example of how to design the high resolution SAR, op amp, and voltage reference for a LEAD I ECG system, click on the following link:
http://www.ti.com/tool/tipd116
To order samples of the ADS8881 or other low power ADCs designed for wearable and portable applications, click on the following product links:
http://www.ti.com/product/ads8881/samplebuy