Wide-Bandwidth High Dynamic Range D/A Converters

Book excerpt: IGH-SPEED Digital to Analog (D/A) converters are essential components in digi- Htal communication systems providing the necessary conversion of signals encoding information in bits to signals encoding information in their amplitude vs. time domain characteristics. In general, they are parts of a larger system, the interface, which c- sists of several signal conditioning circuits. Dependent on where the converter is located within the chain of circuits in the interface, signal processing operations are partitioned in those realized with digital techniques, and those with analog. The rapid evolution of CMOS technology has established implicit and explicite trends related to the interface, and in particular to the D/A converter. The implicit relationship comes via the growth of digital systems. First, it is a global trend with respect to all interface circuits that increasing operating frequencies of digital systems place a similar demand for the interface circuits. The second trend takes place locally within the int- face. Initially, the D/A converter was placed at the beginning of the interface chain, and all signal conditioning was implemented in the analog domain after the D/A conversion. The increasing ?exibility and robustness of digital signal processing shifted the D/A converter closer to the end point of the chain where the demands for high quality high frequency operation are very high.