Mismatch calibration methods for high-speed time-interleaved ADCs

Abstract

International audienceTime Interleaved ADCs (TIADCs) are a good solu-tion to implement high sampling rate converters at a moderate hardware cost. However, they suffer from mismatches between the ADC channels, such as offset, gain, timing skew and possibly bandwidth mismatches. These mismatches have to be corrected in order to get sufficient performances from the converter. This paper presents the classical calibration methods and focuses on the blind ones. Among those, both mixed analog-digital methods and fully digital methods are overviewed. By considering the state-of-the-art of published chips, a comparison between those methods is provided

An All-Digital Timing Mismatch Calibration Algorithm Based on Reference Channel for TIADC

“…where y ′ (n) is the derivative of y(n), similarly, y (5) (n) and y (7) (n) are the fifth-order and seventh-order derivative of y(n), respectively. To enhance the differentiation effect of the derivator, the Richardson extrapolation is employed to construct the higher-order approximation formulas [27].…”

“…Thereinto, the predominant error estimation methodologies entail the utilization of the cross-correlations among sub-channels [2,3,[7][8][9][10][11][12], or the introduction of a reference channel [13][14][15][16]. Based on the correlations among sub-channels, a complex computational matrix is commonly constructed.…”

An Improved All-Digital Background Calibration Technique for Channel Mismatches in High Speed Time-Interleaved Analog-to-Digital Converters

“…Taking the advantages of CMOS scaling and portability between technology nodes, all-digital calibration techniques eliminate the above analog and mixed-signal issues [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31]. These techniques often focus on one or two types of mismatches among the gain and timing mismatches, without the offset mismatch [13][14][15][16][17][18][19][20][21][22][23][24][25].…”