AnsweredAssumed Answered

Correlating Voltage on ADC to 5.19 Format

Question asked by ByronS on Jan 10, 2013
Latest reply on Jan 11, 2013 by KJBob

I have a simple application as part of my project to create a window detector so that when an analog voltage is applied to an ADC input, I create a logic level out to control other functions inside the ADAU1701. I've figured out how to make it work with the Tolerance Analyzer, but there is a portion of this that I don't understand. When I apply a voltage of 2.6 VDC to the ADC, and I do a Readback on the DSP core value, it reports 0.61 decimal. I was easily able to multiply this by a factor to get within the range of the Tolerance Analyzer to make this work, but what is the calculation to determine what the Readback value will be for any given input voltage?

 

After reading several forum posts, and the ADAU1701 datasheet, I see that the full scale range for the ADC is 3.0V. I also undertand that the full scale value for the core is 1. Please also confirm if I'm understanding this correctly.

 

Any insight would be appreciated, since I'm sure it's something terribly simple I'm missing here.

Outcomes