A Time-Domain Method for Pseudo-Spectral Characterization

We present a generic method for determining transfer function of a DUT using simple time-domain computations in place of conventional computationally intensive frequency domain methods. Our method uses a chirp stimulus and an average of absolute value to extract energy in different frequency bins. For an N_o-size spectrum, this enables a reduction of computational complexity from N_o In N_o multiply-accumulates (using an FFT) to N_o accumulates. This makes it an attractive strategy for BIST. We present the theoretical basis, test case simulations, and a comparison with the FFT method.