Digital-to-analog converters (DAC), referred to as decoders in communications terms, are devices by which digital processors communicate with the analog world. Although DACs are used as key elements in analog-to-digital converters, they find numerous applications as stand-alone devices from CRT display systems and voice/music synthesizers to automatic test systems, waveform generators, digitally controlled attenuators, process control actuators, and digital transmitters in modern digital communications systems. The resolution is a term used to describe a minimum voltage or current that a DAC can resolve. The performance of a DAC can be specified in terms of its linearity, monotonicity, and conversion speed. In most conventional DACs, except for the oversampling DACs the linearity and monotonicity are limited by how accurately the reference voltage/current is divided using passive/active components. The output of a DAC is a sampled-and-held stewaveform held constant during a word clock period.