Question

Explain 8-bit r-2r ladder digital to analog converter

Answer 1

The project is an 8-bit digital-to-analog converter that utilizes a resister ladder network to divide current with equal current sources, and an operational amplifier to sum these currents and convert them into an output voltage. The use of an R-2R ladder architecture is very useful for binary-weighted currents. However, the R-2R based converter is easy to implement and the resistance ratio is independent of the number of bits the precision of the resistor is significant. Because the resistance of the R-2R architecture must be so closely matched (as close as 0.01% for the LSB on an 8-bit DAC) and the current ratio through the switches is still large the implementation of current sources is needed. With equal current flow through all the switches the architecture will be slower but more stable.