Abstract — A time-interleaved ADC (TIADC) increases the overall sampling rate by combining multiple slow ADCs. However, the performance of a TIADC suffers from several mismatches such as time, offset, and gain mismatches. This paper deals with the identification and compensation of timing mismatches in a TIADC using the least mean square (LMS) algorithm. The method only requires a bandlimited and oversampled input signal. We present a detailed discussion and demonstrate the effectiveness of the proposed method by numerical simulations. I.

Abstract—Gain and timing mismatches among sub-converters limit the performance of time-interleaved analog-to-digital converters (TIADCs). In this paper we present a blind adaptive method, based on the least-mean-square (LMS) algorithm, to compensate gain and timing mismatches in TIADCs. Similar to other methods in the literature, we assume a slightly oversampled input signal, but, contrary to them, we can apply our method to an arbitrary number of channels in a straightforward way. We give a detailed description of the compensation and the identification part of the method and demonstrate its effectiveness through numerical simulations. I.

Abstract — We introduce spectral shaping of timing mismatches in time-interleaved analog-to-digital converters (TIADCs). We show how to reorder the channel ADC sequence in order to achieve spectral shaping and provide optimization criteria. We present a simple channel sorting algorithm, which significantly improves the signal-to-noise and distortion ratio (SINAD) and the spurious free dynamic range (SFDR) by applying a simple low-pass filter. The power consumption of the presented timing mismatch compensation method is very low compared to other methods and does not significantly scale with the number of channel ADCs. Furthermore, the compensation method does not depend on the absolute accuracy of the identified timing mismatches, which vastly relaxes the requirements on timing mismatch identification methods. analog input xa(t) fs/M fs/M fs/M fs/M

Abstract – We introduce a novel randomization method for timeinterleaved analog-to-digital converters (TIADCs). In contrast to conventional randomization methods our method improves the signalto-noise and distortion ratio (SINAD) and the spurious free dynamic range (SFDR) by combining randomization of channel ADCs and spectral shaping of timing mismatches. The new method can exploit information about timing mismatches of the channel ADCs in order to optimize the randomized sequence. We provide the theoretical background, discuss aspects of the advanced randomization, and present simulation results. analog input xa(t) fs/M fs/M fs/M

Abstract — This paper investigates the adaptive compensation of frequency response mismatches in an M-channel timeinterleaved analog-to-digital converter (TI-ADC) using an extra low-resolution ADC and a time-varying FIR filter. The introduced compensation structure may be used to compensate any linear frequency response mismatches including time skew mismatches. The coefficients of the time-varying filter are adapted using the least-mean square (LMS) algorithm. The performance of the proposed compensation structure is demonstrated through numerical simulations. I.

Abstract- The performance of time-interleaved ADCs (TI-ADCs) mainly suffers from timing mismatches. We introduce an accurate blind timing mismatch identification for bandlimited, oversampled input signals, which is based on a frequency relation between the input signal and the sampled output signal and the fact that timing mismatches are generally small compared to the sampling period. We provide a detailed derivation of the method and discuss questions of implementation and complexity. Finally, we show the potential of the method through

iii ivZusammenfassung Moderne Signalverarbeitungsanwendungen, wie sie in der Nachrichtentechnik und Messtechnik verwendet werden, benötigen sehr schnelle Analog-Digital-Umsetzer (ADU), was durch eine räumlich parallele Anordnung von zeitlich versetzt arbeitenden ADUs (ADU-Array) erreicht werden kann. Die zeitliche Verschiebung ermöglicht, im Vergleich

In this paper, we model time-interleaved analog-to-digital converters (TIADCs) with nonlinear hybrid filter banks (NHFBs), which greatly unifies and simplifies the analysis of TIADCs. The input/output relation of such a nonlinear hybrid filter bank can be used to describe combined offset, gain, aperture delay, input behavior, and nonlinearity mismatches and is therefore an extendable starting point for profound analyses of TIADC behaviors. We show the connection of offset and gain mismatches to nonlinearity mismatches and reveal the two error sources of timing mismatches.

Abstract—In this paper, we present a flexible and scalable structure to compensate frequency response mismatches in time-interleaved analog-to-digital converters (TI-ADCs). The flexibility of the structure allows for designing compensation filters independent of the number of channels that can achieve any desired signal-to-noise ratio due to the scalability of the structure. Therefore, the compensation structure may be used to compensate time-varying frequency response mismatches in TI-ADCs, as well as to reconstruct uniform samples from nonuniformly sampled signals. We analyze the compensation structure, investigate its performance, and demonstrate application areas of the structure through numerous examples. Index Terms—Analog-to-digital converter (ADC), compensation, frequency response mismatches, reconstruction, time-interleaved, time-varying filter. I.

Digital signal processing for data converters in mixed-signal systems