Burr-brown Research Corporation

Theodore L Williams

Paul R Prazak

A digital to analog conversion system includes a memory for storing a plurality of correction codes corresponding to corrections required to compensate for inaccuracy in output currents of a main digital to analog converter (DAC) contained in the digital to analog conversion system. A plurality of the logic inputs applied to the inputs of the main DAC are also applied to the address inputs of the memory. A trim DAC having its inputs coupled to the data outputs of the memory converts the correction code stored in the addressed location of the memory into a correction current which is utilized externally of the main DAC to modify the net amount of output current available from the main DAC to compensate for inaccuracy of the unmodified output current. An output signal from a temperature sensor is connected to a digital number which is also applied to a plurality of the address inputs. Correction codes stored in locations addressable in response to the temperature sensor have values which effect adjustment of the correction current to compensate for inaccuracy of the output current due to temperature variations. A self-calibration system and method which updates the correction codes stored in the memory are also disclosed.

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Tucson, AZ, United States of America

Theodore L Williams