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

A digital-to-analog conversion method having signal calibration mechanism used in a digital-to-analog conversion circuit that comprises a plurality of thermometer-controlled current sources that generate an output analog signal according to a total current thereof and a control circuit, the digital-to-analog conversion method comprising:

• retrieving a plurality of current offset values that the thermometer-controlled current sources correspond to by the control circuit;
• performing a sorting procedure on the current offset values to generate a turn-on order by the control circuit, wherein the current offset values are separated into a plurality of current offset groups according to the turn-on order, in which signs of each neighboring two of the current offset groups are opposite such that the current offset values cancel each other when the current sources turn on according to the turn-on order to keep an absolute value of a total current offset value of the current offset values not larger than a half of a largest absolute value;
• and
• controlling the current sources to turn on based on the turn-on order by the control circuit according to a plurality of thermal codes comprised by an input digital signal.