4 Summary

High-speed ADCs are essential components in modern digital systems, but ADC accuracy can be compromised by various errors. Calibration, which addresses gain, offset, linearity, and spurious components such as HD2 and HD3, plays a crucial role in improving the spurious-free dynamic range or SFDR of the ADC. Achieving a high SFDR is particularly important in systems operating at lower transmit powers or over longer distances, as a high SPDR helps distinguish desired signals from unwanted spurious components. Internal ADC calibration schemes have emerged as effective solutions to minimize these errors and enhance ADC performance. However, factors like temperature variations, power supply fluctuations, and IC process shifts can degrade or compromise calibration. One-time calibration establishes a solid starting point, while foreground and background calibrations maintain accuracy in the presence of varying environmental conditions. System designers must understand and implement the appropriate calibration technique to reduce harmonic distortion, improve SFDR, and achieve accurate measurements with high-speed ADCs in future designs.