how to configure the ADC using whatever Vref exterior

[davidmartínezag]

Hi!!!

I am configuring a ADC for a current sensor using a chip for it. The issue is that uses a voltage divider with a Vref of 3V. When i do the calculations I use this value coming out the result wrong, it debit to the microcontroller taking the value of voltage feeding microcontroller.

If someone could help me to know how to configure to use the Vref I want to I will be pleasent.

Thanks for advance

[david_diaz]

Hello David,

The input voltage range of an ADC is determined by the reference voltage (VREF) applied to the ADC. A reference voltage can be either internal voltage or external voltage by applying a voltage on an external pin of the microcontroller. Generally reference voltage can be selected by configuring the corresponding register’s bit field of the microcontroller. ADC will saturate with an analog voltage higher than the reference voltage, so the designer must make sure that the analog input voltage does not exceed the reference voltage.

For proper conversion, the input voltage must fall between the reference voltages: VREFH and VREFL.

If the input is equal to or exceeds VREFH, the converter circuit converts the signal to 0xFFF.

Besides, the VREF must not exceed the VDDA value.

I hope this information will be useful for you.

If I misunderstood your question, feel free to let me know.  I will be glad to help.

Have a great day.

David Diaz.