A Digital Calibration Technique for the Correction of Glitches in High-Speed DAC's

The accuracy of high-speed DAC's is limited by dynamic effects such as glitches. Here, a digital calibration technique to compensate this effect is presented. Because of the digital approach, this solution can not be an exact correction of the phenomenon, but a band limited attenuation. The approach consists of adding a (digital) compensation signal to correct the glitch. Both a 2-tap and a 4-tap correction are investigated and it is shown that they can greatly reduce spurs over a bandwidth of 30% and 60% of the Nyquist band respectively, provided the glitch energy is known. Next, it is shown how an adaptive calibration with an additional low-speed calibration ADC can be used to estimate the glitch energy. Simulations confirm that the spectral performance can be greatly improved this way.