Smillsey
Member level 5
Hi all
I am interested as to what your approach is when selecting a voltage reference for your ADC’s?
Imagine you have selected a suitable ADC and it’s Vref Range is max 5V.
Should I find a voltage reference with that exact output?
What if I cannot find a reference with a good enough drift characteristic that exactly match the 5V Vref requirements, what if I want to use a Vref with 7V or 10V output due to their drift performance?
1. Is it bad practice to change the output reference voltage of a fixed reference with an external attenuators circuit placed before the input of the ADC?
2. If this is accepted, I have the following concerns;
a. Need to place capacitor close to Input of adc on order to furnish the adc with inrush current during conversion
b. thermal drift of any attenuators circuit could ruin performance of reference
c. Not sure whether to go for an op amp type attenuation circuit for resistor divider + cap.
Any help would be greatly appreciated
Thanks!
S
I am interested as to what your approach is when selecting a voltage reference for your ADC’s?
Imagine you have selected a suitable ADC and it’s Vref Range is max 5V.
Should I find a voltage reference with that exact output?
What if I cannot find a reference with a good enough drift characteristic that exactly match the 5V Vref requirements, what if I want to use a Vref with 7V or 10V output due to their drift performance?
1. Is it bad practice to change the output reference voltage of a fixed reference with an external attenuators circuit placed before the input of the ADC?
2. If this is accepted, I have the following concerns;
a. Need to place capacitor close to Input of adc on order to furnish the adc with inrush current during conversion
b. thermal drift of any attenuators circuit could ruin performance of reference
c. Not sure whether to go for an op amp type attenuation circuit for resistor divider + cap.
Any help would be greatly appreciated
Thanks!
S