ON-CHIP CALIBRATION CIRCUIT AND METHOD WITH A HALF-STEP RESOLUTION

摘要

A calibration circuit and calibration method are disclosed. The circuit includes: a DAC that outputs an analog parameter and has an output parameter setting circuit; a comparator that receives a reference parameter and the analog parameter; and a control circuit (with selection logic) connected to the comparator and the DAC in a feedback loop. In a calibration mode, the size of the analog parameter is adjusted by half a DAC step in one direction and the feedback loop is used to perform a binary search calibration process. In an operating mode, the size of the analog parameter is set by half a DAC step in the opposite direction. The selection logic selects the DAC step identified by the calibration process or the next higher DAC step as the last DAC step. The control circuit outputs a final DAC code that corresponds to the final DAC step, and the DAC generates a calibrated parameter based thereon.