ADC Accuracy

[MAnsa.1]

Hi Guys, i am using STM8S003F3 controller and i want to that how can i achive 0.1v accuracy when my ADC resolution is 1023 and my total count is 2000.

[Ozone]

Read the datasheet / reference manual of the STM8.

Absolute resolution is reference voltage divided by number of steps.

[MAnsa.1]

yes you are right 5/1023=4.9mV and step size is total count/2^n-1=2000/1023=1.955.so i can get this accuracy but i want to know is there anyway to get 0.1v accuracy ??

[Ozone]

> ... and my total count is 2000.

I don't know what you mean with that.

Check the datasheet for Vref options. Vref is not necessarily Vdd or Vdda.

Otherwise, you can only get Vref/2^n, i.e. Vref/1024 for the 10-bit ADC your controller has.

> ... but i want to know is there anyway to get 0.1v accuracy ??

Do you really mean 0.1V meaning 100mV ?

Then just scale down the result.

[Tesla DeLorean]

Also confused here, how can a 10-bit value be 2000?

Or are you averaging 2000 samples? In which case I don't understand your computation.​

[MAnsa.1]

2000 count is not an ADC value it is my total input count that is +1000 and -1000 input volt mean total 2000count.

[MAnsa.1]

how do i scale it? any sample do u have??

[Ozone]

It is still not clear where you pull that number from.

In relation the 10-bit ADC, this is nonsensical.

[Tesla DeLorean]

You have a 2KV swing on the input!! I don't expect you're going to be able to do that directly, or get the accuracy/precision with that few bits on your ADC​

[MAnsa.1]

that +1000 and -1000 is my input range that i will apply to the ckt.i t will come from by user end.