Timeline for Reading ADC value with uV Reference voltage
Current License: CC BY-SA 4.0
9 events
| when toggle format | what | by | license | comment | |
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| Nov 21, 2019 at 0:36 | comment | added | MarkU | With such poor linearity, there is no value in trying to cascade these ADCs. The INL and DNL are just barely adequate for a cheap 12-bit SAR ADC. You’re better off buying an external delta-sigma ADC to get high 24-bit resolution with appropriate dynamic range for the signal you want to measure. Many delta-sigma ADC are available with internal PGA (amplifier), which is more likely what you actually need. | |
| Nov 20, 2019 at 22:54 | comment | added | neerajb | The MCU is ATXMEGA256A3U. It has a 12-bit ADC which can be configured for 8-bit and 10-bit with single-ended and differential mode. I was wondering if we lower the reference voltage, it will improve the resolution but the reference voltage cannot go below 1V. Which is why I probably have to get an external ADC. I can amplify the signal which is basically taken from a chemical reaction and should be around 0.5V but to improve the resolution from 8 to 16 bit or even 12 to 24, I don't think ADC will be able to take in that large of a value. Let me know if I'm not clear about something. | |
| Nov 20, 2019 at 21:57 | comment | added | Marcus Müller | @neerajb Really, describe what you're trying to do: You don't get better measurement resolution by making your measurement device worse, but by increasing the signal amplitude, you really have some misconceptions. I bet some of the challenges you face are easy to solve, but you just leave us in the dark. Don't do that! | |
| Nov 20, 2019 at 21:44 | vote | accept | neerajb | ||
| Nov 20, 2019 at 21:43 | comment | added | neerajb | The minimum reference voltage should be 1V. That means I won't be able to improve the resolution by lowering the reference. I guess that answers my question. | |
| Nov 20, 2019 at 21:17 | history | edited | The Photon | CC BY-SA 4.0 |
added 179 characters in body
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| Nov 20, 2019 at 21:14 | comment | added | The Photon | @MarcusMüller, and never mind that the noise floor is probably above 50 uV, and ... | |
| Nov 20, 2019 at 21:12 | comment | added | Marcus Müller | And half of the input range won't sensibly be quantized, if OP's input voltage range is actually symmetric around 0V... | |
| Nov 20, 2019 at 21:12 | history | answered | The Photon | CC BY-SA 4.0 |