An Efficient All-Digital Timing Skew Estimation Method for Time-Interleaved ADCs

Timing skew mismatch in time-interleaved analog-to-digital converters (TIADCs) greatly degrade the dynamic performance of the TIADC, which can be improved effectively by digital estimation and correction methods. In this paper, an efficient all-digital timing skew estimation method for
M
-channel TIADCs is proposed. Through Hilbert filtering and inverse trigonometric calculation, timing skew mismatch can be estimated at one time by injecting a known test sinusoidal signal. Compared with the previous foreground method, the proposed technique has a higher computational efficiency and looser limitations. Simulation results show that, for a four-channel 10-bit TIADC model, with
f
_in
/
f
_s
= 0.347, signal to noise and distortion ratio (SNDR) and spurious free dynamic range (SFDR) are improved from 29.5dB and 31.1dB to 61.9dB and 85.8dB, respectively.