Digital-to-analog conversion apparatus and method having signal calibration mechanism

A digital-to-analog conversion method having a signal calibration mechanism, used in a digital-to-analog conversion apparatus, comprising:

• performing digital-to-analog conversion according to a signal feeding related to an input digital signal having a set of input codeword by a conversion circuit comprising a plurality of current sources operating under a first frequency, to generate an output analog signal, wherein the input digital signal comprises N input parts arranged in an order with an equal size, N being a positive integer larger than 1;
• performing signal processing that comprises down-sampling on an echo path by an echo transmission circuit to generate an echo signal having a second frequency, wherein the second frequency is 1/N of the first frequency;
• receiving a piece of selected data of one of the N input parts as a pseudo noise feeding and a plurality of pieces of non-selected data as a signal feeding by each of N calibration circuits operating under the second frequency comprised by an echo calibration circuit, to perform mapping according to a plurality of offset tables and perform processing according to a plurality of groups of response coefficients to generate one of N calibration parts of a calibration signal;
• and
• generating a plurality of offsets according to an error signal between the echo signal and the calibration signal and path information related to the echo calibration circuit by a calibration parameter calculation circuit operating under the second frequency;
• and
• making the groups of response coefficients converge according to the error signal and pseudo noise transmission path information from the conversion circuit to the echo transmission circuit, and further updating the offset tables according to the offsets by the echo calibration circuit.