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 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.