论文信息 - Off set-Compensation of Switched-Capacitor Two-Phase Filters

Off set-Compensation of Switched-Capacitor Two-Phase Filters

Absstruct-Tkis paper describes a novel method for rejection of low- frequency and offset signals in two-phase switched-capacitor filters. Also offset compensation using reset cycles is treated. It applies to all switched- capacitor structures where a dc-path can be found from a node inside the filter to the output. The idea is to connect an offset-free integrator in a feedback loop within the original filter structure. The net effect of the loop for continuous-time applications is to give an overall high-pass response. The resulting transfer function distorsion cm be compensated for to first order by making a small change of one capacitor. Design examples are given for a leapfrog and a cascaded biquad filter. Experimental breadboard designs and computer simulations have verified the applicability of the method.

Svante Signell | Kare Mossberg

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