Digital correction of A/D conversion error due to multiplexing delay

A measurement channel that consists of a multiplexer, sample-and-hold circuit, and analog-to-digital (A/D) circuits is designed for the synchronous sampling and measurement of two or more voltage signals (V₁(t), V₂(t), . . .). The finite time of A/D conversion (T) makes it possible to acquire samples of V_i+1(t) closer in time than T. This can become a source of measurement error if further processing of the measurement data is based on the assumption of ideal synchronism. It is shown that interpolation filters, developed from the Lagrange polynomial interpolation, are useful tools for solving the problem of correction. An illustrative example is presented