A digital-to-analog converter, or DAC, turns a digital code into an analog output level. Resolution describes the number of available code steps. For a common ideal unipolar transfer, output = reference × code / 2^N. The highest code is one step below the reference, not equal to it.
Worked example
For an ideal four-bit DAC with a 3.2 V reference, one LSB is 3.2/16 = 0.2 V. Code 1010 is decimal 10, giving 2.0 V. Code 1111 gives 3.0 V. Actual devices add offset, gain, linearity and settling errors.
What to watch for
Read the device's transfer function: some architectures use different ranges or scaling. Bit resolution alone does not guarantee equivalent analog accuracy.
Try it yourself
Using the example DAC, what output corresponds to code 0101?
Answer: Code 5 produces 5 × 0.2 V = 1.0 V under the stated ideal model.
How to study this topic
Separate the ideal logical model from the physical device interface. Write units beside capacities, voltages and timing values. The architecture explains the idea; the chosen part's documentation supplies the operating limits.
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Digital Electronics