What is a key practical advantage of the R-2R ladder DAC's standard resistor network?

• A. It provides non-monotonic steps that can be adjusted easily.
• B. It requires extremely precise resistor matching for accuracy.
• C. It scales poorly with more bits due to increasing mismatch.
• D. It scales to high bit-depth with a simple, repeatable ladder using only two resistor values.

Answer: (D)

The practical win with the R-2R ladder DAC is its scalability using just two resistor values. You build the DAC from repeating ladder sections that use only R and 2R. When you need more bits, you simply add more identical sections; you don’t have to mix in a lot of different resistor values or redesign the network. This makes manufacturing easier and cheaper, and it keeps the circuit predictable as you increase resolution. The ladder also presents a stable input impedance (roughly equal to R) regardless of how many bits are tied to Vref or ground, which helps the driver stage.

So, extending to higher bit-depth with a simple, repeatable ladder using only two resistor values is the key practical advantage.