Part Number: ADS1299 Hi Folks, I'm working on an EEG !!! like !!! project, where I have to digitalize 2mVpp signals with high resolution as possible. The facts confused me: From the datasheet of ADS1299 , I figured out, that the internal reference is 4.5V respect to AVSS (chapter 9.3.1.3.4). According to chapter 9.3.1.3.2, the FS should be 2 * 4.5V / 24Gain = 0.375V. EEG signals are about 10uVpp so the input FS is 40000 times larger than necessary. For me, it implies that the effective resolution is far smaller than 24 bit. On the other hand, I studied the OpenBCI project ( ). They are also using this AD converter without input amplifier and the TI reference design and the datasheet also suggest this way, and it seems to works. Can anybody explain me, why should I left the input amplifier, or in my case should I use one? Once again: my goal is to digitalize 2mVpp biological signals with high resolution as possible. Regards, Norbert
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