16 bit error-correcting digital-to-analog converter

摘要

An improved digital-to-analog conversion circuit (10) comprises digital circuitry (12) for receiving digital input signals from a digital input signal source, conversion circuitry (42) receiving the digital input signals and producing analog output signals and analog output circuitry (44) for sending analog output signals to an analog output signal load. The conversion circuit (10) includes calibration circuitry (46) that samples analog output signals from analog output circuitry (44) and includes a reference signal source (52) for producing a plurality of reference signals. A comparator (50) compares a predetermined aspect of the analog output signals to the reference signals to produce therefrom a plurality of difference signals. Correction circuitry includes error detection circuit (95) that includes a successive approximation register (62) and a digital controller (66) for receiving the difference signals and a digital interpolator (26) for generating a plurality of correction signals. The digital interpolator (26) receives the correction signals in response thereto and sends signals to a vernier digital-to-analog converter (38) to precisely control the analog output signals from conversion circuitry (42).