Title :
Shifting the frequency response of switched-capacitor filters by nonuniform sampling
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., California Univ., Davis, CA, USA
fDate :
1/1/1991 12:00:00 AM
Abstract :
A clock with nonuniformly spaced sampling times can be used to shift the frequency response of switched-capacitor filters. By using such a clock, which deviates only slightly from a uniform sampling clock, small shifts in the frequency response of a switched-capacitor filter can be realized. The nonuniform sampling generates undesired modulation sidebands which are small if the deviation from uniform sampling is small. Computer simulations and measured data are presented to support equations that predict the frequency response shift and the amplitude of the undesired sidebands. This technique can be used to correct frequency response errors in monolithic switched-capacitor filters caused by capacitor ratio inaccuracies. It may also be useful in applications such as spectrum analyzers and tone generators
Keywords :
frequency response; switched capacitor filters; SC filters; active filters; capacitor ratio inaccuracies; clock; error correction; frequency response; frequency response shift; modulation sidebands; monolithic filters; nonuniform sampling; nonuniformly spaced sampling times; spectrum analyzers; switched-capacitor filters; tone generators; Clocks; Computer errors; Computer simulation; Equations; Error correction; Filters; Frequency measurement; Frequency response; Nonuniform sampling; Sampling methods;
Journal_Title :
Circuits and Systems, IEEE Transactions on
