Patent ID: 8125361
Filing Date: 2012-02-28
Classification: H03M

Abstract:
1. A digital-to-analog converter (DAC) calibration system comprising: a multiplexer receiving a digital input sequence and outputting a first digital signal and a plurality of second digital signals, wherein the first digital signal is orthogonal to the second digital signals; a first current source switch (CSS) element having: a plurality of second current source switch (CSS) elements each having: an output node coupled to the first weighting network and the second weighting networks, receiving the first output current pulse and the second current pulses, the combination of which forms a total output current pulse; a resistive element coupled between the output node and a ground source, conducting the total output current pulse to the ground source to produce an output voltage on the output node; a first calibration module configured to receive the first digital input and convert the output voltage to a target voltage having an average output voltage value that reflects the first output current magnitude; an average measurement module coupled to the first calibration module and configured to measure the average output voltage value; and a second calibration module coupled to the average measurement module and configured to compare the average output voltage value with a predefined voltage value and adjust the bias voltage to control the first current source and the second current sources.