A Fast Convergence Second-Order Compensation for Timing Skew in Time-Interleaved ADCs

Dengquan Li, Lei Zhao, Longsheng Wang, Yi Shen, Zhangming Zhu

2022IEEE Transactions on Very Large Scale Integration (VLSI) Systems26 citationsDOI

Abstract

This brief presents a digital background calibration technique for timing skew in time-interleaved (TI) analog-to-digital converters (ADCs). It updates the calibration step adaptively based on the detection error. This results in large update step initially, and it reduces with the calibration cycle going on. More than two times convergence time is saved compared with the conventional fixed update step method. Besides, by extending the compensation to second-order, both calibration range and accuracy are improved. To demonstrate the effectiveness of the proposed timing skew calibration, extensive simulation and measurement results are provided. It shows that after timing skew calibration, the signal-to-noise and distortion ratio (SNDR) and spurious free dynamic range (SFDR) of a two-channel prototype TI ADC are improved by 8.2 and 14.9 dB, respectively.

Topics & Concepts

SkewSpurious-free dynamic rangeCalibrationConvertersCompensation (psychology)Computer scienceDynamic rangeElectronic engineeringDistortion (music)Convergence (economics)Noise (video)Spurious relationshipEngineeringMathematicsCMOSElectrical engineeringTelecommunicationsAmplifierPsychologyArtificial intelligencePsychoanalysisEconomicsMachine learningStatisticsEconomic growthImage (mathematics)VoltageAnalog and Mixed-Signal Circuit DesignCCD and CMOS Imaging SensorsAdvancements in PLL and VCO Technologies