Lab 6

Lab  6   Digital to Analog Converter       

                  1. Purpose  

         Construction of digital-to-analog converters using different techniques, namely the scaled
          resistors into summing junction, and the R-2R ladder.

                  2. Converting Digital to  Analog Signals

                        2.1   Scaled resistors into summing junction

                        2.2   R-2R ladder

       Rubric  for Lab-6

It is often necessary to convert analog signal to an accurate digital number, and vice versa. For example, in applications where a microprocessor is controlling an experiment, the analogue signal from a sensor needs to be converted into digital form so it can be communicated to the microprocessor. After the processing takes place in the digital form, the output from the microcontroller needs to be converted back to the analogue form to communicate with the analogue world.

In this lab session we will consider the case of digital to analogue conversion (DAC). The DAC techniques presented here are not aimed at developing skills in converter designs. Instead, they aim at presenting the advantages and disadvantages of each method. In most cases, when embarked in an electronic project, one rather buys commercially available chips instead of building a converter from scratch. An understanding of DAC methods, however, will guide you in selecting the more suitable one for the project at hand.

       Complementary information
                                The ADC/DAC  CN0554 device
                                Analog-to-digital conversion: The CN0554 features the AD7124-8, a 24-bit Σ-Δ ADC
                                Digital c-to-analog conversion: The CN0554 features 16 single-ended, 16-bit analog
                                outputs using the LTC2688 voltage output DAC.