ADM1066: application questions

Document created by analog-archivist Employee on Feb 23, 2016Last modified by analog-archivist Employee on Feb 23, 2016
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1. In the closed-loop margining application as showed in Figure 33 in
datasheet, if  DACOUTn is placed with midcode at 1.0V, DC/DC output (VPn) is
supposed to be 3.4V as normal voltage, and we want to get %5 up and down margin
at OUTPUT, so what values of R1, R2, R3 are typical? 
2. In this context,  what should the input range of DC/DC converter’s feedback
pin be?
3. Please describe the details of the ADC conversion when using averaging mode.
We want to know clearly whether the value we read from ADC is the sum of 16
times reading, or just the average of these readings.
4. Please give us some example driver code for the ADC reading when using
averaging mode.

 

Answers:
1.R1 and R2 values changes with different convertors. So I can't comment on R1
and R2 without knowing  which converter is being used.  R3 will then depend on
the value of R1, R2.  The datasheet for the converter in question should have a
table or a formula for calculating the resistor values required for a 3.4V
nominal output.
2. Again, I can't comment until I know the resistor values.
3. The ADC round robin reads each channel in turn 16 times, it then takes the
average of the summed result.
4. Please find attached a document which will help you with the ADC coding.

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