A Hilbert-Transform-Based Method to Estimate and Correct Timing Error in Time-Interleaved ADCs

Abstract

In time-interleaved analog-to-digital converter (ADC) architecture, offset mismatch, gain mismatch, and timing error between channels degrade the performance of time-interleaved ADCs. This paper focuses on the timing error, and proposes a simple calibration algorithm based on Hilbert transform estimate and then correct the timing error. With a cosine input, it could efficiently and accurately estimate the timing error. Fractional delay filters are developed to correct the timing errors. This simplifies the design and decreases the cost. Numerical simulations are used to verify the proposed estimation and correction algorithm.

Effective extraction method for triple errors in foreground calibration of TI‐ADCs

“…The interpretation of (20) depicts that the first term on the right side of equality is the representation of timing skew mismatch. The second term illustrates the gain error just as obtained in (14), while the fourth phrase pertains to the offset mismatch. The third term, which is the product of timing skew and gain mismatches, is small enough to be neglected.…”

“…A comprehensive literature review depicts that many state-of-the-art architectures have been reported over recent years for the foreground calibration of TI-ADCs. [13][14][15][16][17][18] Even though the main objective was to reduce the utilized hardware, few of them slightly managed to achieve such a goal because specific signal reconstruction procedures are needed as a substitution for the reference ADC. For a better realization of the issue, the specifications of those systems have been summarized in Table 1.…”

“…There are many state-of-the-art structures for the foreground calibration of TI-ADCs where each scheme has its benefits and drawbacks. [13][14][15][16][17][18] However, a thorough analysis depicts that the complicated hardware for the calibration of timing skew is the common drawback of these systems. Besides, the need for a general-purpose calibration algorithm for the triple errors becomes vital, knowing that each type of ADC structure suffers from an error more than the other mismatches.…”

“…There are many state‐of‐the‐art structures for the foreground calibration of TI‐ADCs where each scheme has its benefits and drawbacks 13–18 . However, a thorough analysis depicts that the complicated hardware for the calibration of timing skew is the common drawback of these systems.…”

A Nonlinear Calibration Method Based on Sinusoidal Excitation and DFT Transformation for High‐Precision Power Analyzers

“…The calibration uncertainty of this system reaches 0.038% within the measuring range. The hardware compensation method circuit [8,9] is usually complicated, and the circuit design process costs much. Besides, the calibration range is small, and the accuracy cannot be guaranteed within the entire range.…”