Abstract: A method for automatic adjustment of sampling phase includes the steps of: (a) setting a predetermined number of test phase divisions for each of a plurality of sampling pulses from a sampling circuit; (b) controlling the sampling circuit to sample an analog test signal within a sampling period using the sampling pulses, determining an active sampled data length corresponding to each of the test phase divisions of the sampling pulses by detecting start and end of the analog test signal for each of the test phase divisions of the sampling pulses, and detecting at least one set of consecutive ones of the test phase divisions that have a shortest active sampled data length corresponding thereto; (c) determining an optimum test phase as a central one of the test phase divisions in the detected set that includes a largest number of the consecutive ones of the test phase divisions; and (d) providing the optimum test phase to the sampling circuit to enable the sampling circuit to perform sampling phase adjustment ba