Hi Team,
I saw some ADCs use 1.2 or 1.25V internal Vref, and some use 2.5V.
May I know what reason or concern to use different internal reference voltage for them?
Thanks.
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Hi Team,
I saw some ADCs use 1.2 or 1.25V internal Vref, and some use 2.5V.
May I know what reason or concern to use different internal reference voltage for them?
Thanks.
Hi Peter,
this is not a straight forward answer.
In some cases we have a certain voltage reference IP available in a certain process node that we then reuse for certain ADC designs in that process. Other times the delta-sigma modulator IP we have available doesn't work with a certain reference voltage level. Then the supply voltage range we use for the ADC could also limit the reference voltage we use. E.g.a device that only supports up to 1.8V supply, wouldn't work with a 2.5V VREF.
For typical industrial applications we often times try to use a 2.5V VREF. In test&measurement applications we tend to use 2.5V or even 4.096V VREFs.
In applications where most likely only very small signals need to be measured, we chose smaller VREF voltages in the past.
Regards,
Joachim Wuerker