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.