ABSTRACT
The aim of this chapter is to introduce the principles and circuits used in the design of analogue-to-digital and digital-to-analogue converters. The first interface device to be covered is the digital-to-analogue (D-A) converter. Its function is to convert a digital input codeword into a signal that can be processed by analogue circuits, and so it forms the output interface from a digital to an analogue subsystem. Hence the choice of binary-weighted resistor values for the network has led to the natural binary relationship between the input codeword and the output voltage. Such binary-weighted resistor networks are frequently used in discrete component D-A converters, because of their simplicity. In most of the D-A converter designs we have examined so far the output voltage has been negative. This is because the reference voltage was chosen to be positive and, with the exception of the circuit in Self-assessment question 3, the D-A converters have employed inverting amplifiers.
