Why use bandgap reference voltage 1.024V???

[diarmuid]

Hello!

I have seen bandgap voltages of 1.024V being used by ADC's, where the other analog blocks make do with 1.2V.

Why does an ADC need such a reference voltage? Its something to do with 2^10 I presume, but not being an
ADC guru, I cant say what!

Thanks in advance,

Diarmuid

 

[erikl]

You're right. So LSB=1mV .

 

[ducvilla]

Hi diarmuid!

So, why 1.024V, it's for 1LSB => good for standardization of ADC. ;-)
And normally, this is reference voltage, i think it should not be called bandgap ref voltage, because the typical bandgap voltage is between 1.2 - 1.3 V, it is based on the theoretical value for silicon is 1.22eV at 0K.