Hi WorkerBee, Sorry I couldn't get to you last week. You've done a great job of digging into this yourself, but let me cover a few points you made. I should clarify the benefits of oversampling. Oversampling improves effective number of bits (ENOB) by means of noise reduction (improving SNR). Given a DC signal, oversampling will decrease the variability in your measurement. This is important if errors from uncorrelated noise (white noise) are your limiting factor, but this does not determine the actual accuracy of the ADC, where linearity is more important. For deeper discussion of that, I would direct you Part 1 and Part 2 of the ADC Accuracy E2E blog posts. I'd like to hear any feedback or lingering questions you have from those posts, and hopefully we can help clarify them in future content. I would also recommend looking at the " Resolution-Boosting ADS7138 Using Programmable Averaging Filter " application brief, which has good information related to oversampling, not necessarily specific to the ADS7138. Hopefully these answer your questions regarding oversampling. Maybe I misled you in stating that the smaller RC is always preferable. In your case, it is better to have a larger capacitance if you are sampling a slow moving signal on a single channel, and you are only sampling once in a while. Something to consider is that the first conversion on power-up should consider the time it takes for the capacitor to reach the final value. The Driving SAR ADC without amplifiers TI Precision Labs video actually does a great job of explaining what use cases you can get away with without an amplifier, and the calculations necessary to safely make design choices. After properly calculating, the ADS7044 common-mode rejection ratio does drop the amplitude of the 200mV noise you see to under 1 LSB at 3.3V AVDD, and the low-pass filter in front of the ADC should attenuate it even more. Given that, I do agree that you can achieve more noise-free bits from averaging. Offset errors can usually be calibrated for if need be, but realistically, these errors aren't often the limiting concerns when discussing 12-bit ADCs or lower. In your case, considering other errors introduced , signal conditioning may not be worth it. Regards, Joel
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