This paper proposes improved switched-capacitor (SC) interpolators using a
novel sampling technique which eliminates the undesired distortion due to t
he sample-and-hold shaping effect Lit the lower input sampling rate. Such a
sampling technique not only leads to a precise analog interpolation, as it
s digital counterpart does, but also allows to simplify the design procedur
es and resulting SC circuit implementations. Different circuit topologies w
ith both finite- and infinite-impulse response characteristics are develope
d, respectively, for low- and high-selectivity filtering, Practical impleme
ntation issues are discussed with respect to capacitance ratio mismatches,
as well as finite gain, bandwidth, and offset sensitivity effects of operat
ional amplifiers. Besides detailed computer-based analyses, experimental re
sults obtained from discrete component prototypes are also presented to dem
onstrate the proposed circuits.