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I have a current sensor (sensitivity is 22mV/A) which is being used to measure AC current with its time stamp data.
I have connected this sensor to an ADC (12 Bits resolution
Can somebody please let me know whether we can measure an AC sinusoidal current as low as 0.3A with its time stamp data (like input side of a mobile charger from 2-Pin socket), I would be very much appreciative.
Let's see.
22mV/A * 0.3A = 6.6mV
So your 0.3A RMS AC current will produce a 6.6mV RMS AC voltage at your ADC input. It is a 12-bit ADC. So if the ADC reference is 5V, then the resolution of the ADC is:
5/(2^12-1) which is 5/4095 = 1.22mV
So you will be trying to measure a 6.6mV (rms) signal with a 1.22mV resolution ADC. In practice this will not work super well. The current error, when you include all sources of error, will probably be pretty large. A 0.3A AC current may be detectable, but you will be unable to distinguish between a 0.3A current and a 0.4A current or 0.2A.
Using a lower reference voltage may help. There is another potential problem in that you have to make sure the output of the sensor is in the allowable range of the ADC inputs. If the ADC can measure 0-5V, then you need to make sure the sensor is always between 0 and 5V. If the ADC can only measure 2.5V, then you need to make sure your signal is always under 2.5. Etc.
time stamp data, whatever that actually is \$\endgroup\$