Question

A typical A/D converter has 12-bit resolution and a full range of 10 volts. What is the percent resolution and voltage resolution of this device? What stored data point will I get for a sampled value of 7.3 volts?

Answer 1

Answer: a) 0.024 % b) 2.44 mV c) 2,990 = 11110101110

Step-by-step explanation:

Assuming that all steps are equal each other, if the A/D converter has 12-bit resolution, this means that any voltage will be represented by a combination of 12 bits, i.e., 2¹² levels.

Now, 2¹² = 4,096 levels.

If we divide 10 volts between 4,096, and take the percentage, we get that each level represents a 0,024 % of the full scale value.

So, taking 10 V as full scale value, and dividing between the 4,096 levels, each sampled value will represent 2.44 mV.

Assuming that the binary value with all 0's represent the lowest value of the range, and that all 1's represent the highest one (10 V), a value like 7.3 V will be sampled as 2,990, which has this binary representation:

11110101110

With this representation scheme, any sampled value will be stored with an maximum error of half of the step size, i.e., 1.22 mV.