### Q

1. In the closed-loop margining application as showed in Figure 33 indatasheet, 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.

### A

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.