To significantly increase the sampling rate of an A/D converter (ADC), a time interleaved ADC system is a good option. The drawback of a time interleaved ADC system is that the ADCs are not exactly identical due to errors in the manufacturing process. This means that time, gain and offset mismatch errors are introduced in the ADC system. These errors cause distortion in the sampled signal.In this paper we present a method for estimation and compensation of the mismatch errors. The estimation method requires no knowledge about the input signal except that it should be band limited to the Nyquist frequency for the complete ADC system. This means that the errors can be estimated while the ADC is running. The method is also adaptive to slow changes in the mismatch errors. The estimation method has been validated with simulations and measurements from a time interleaved ADC system. In this paper we present a method for estimation and compensation of the mismatch errors. The estimation method requires no knowledge about the input signal except that it should be band limited to the Nyquist frequency for the complete ADC system. This means that the errors can be estimated while the ADC is running. The method is also adaptive to slow changes in the mismatch errors. The estimation method has been validated with simulations and measurements from a time interleaved ADC system. Keywords
Abstract-To significantly increase the sampling rate of an A/D converter (ADC), a time interleaved ADC system is a good option. The drawback of a time interleaved ADC system is that the ADCs are not exactly identical due to errors in the manufacturing process. This means that time, gain and offset mismatch errors are introduced in the ADC system. These errors cause distortion in the sampled signal.In this paper we present a method for estimation and compensation of the time mismatch errors. The estimation method requires no knowledge about the input signal except that it should be band limited to the foldover frequency, π/T s, for the complete ADC system. This means that the errors can be estimated while the ADC is running. The method is also adaptive to slow changes in the time errors.The Cramer-Rao bound for the time error estimates is also calculated and compared to Monte-Carlo simulations. The estimation method has also been validated on measurements from a real time interleaved ADC system with 16 ADCs.
Parallel AD converter structures is one way to increase the sampling rate. Instead of increasing the sample rate in one AD converter, several AD converters with lower sampling rate can be used instead. A problem in these structures is that the time between samples is usually not equal because there are errors in the delays between the AD converters. We will here present a method to estimate the timing offset errors. The estimation algorithm works without any special calibration signal, instead the normal input signal is used. The only assumption that we need on the input signal is that most of the energy is concentrated to a low pass band, below about 1/3 of the Nyquist frequency. Simulations of the time interleaved AD converter show that the method estimates the errors with high accuracy.
A previously presented method for estimation of time errors in timeinterleaved A/D converter systems is here verified on measurements from a dual A/D converters system. The advantage of this estimation method, compared to other methods, is that it does not require any knowledge about the input signal. The estimation is most accurate for slowly varying input signals but the signal quality is improved even when the estimation is done for a sinusoidal signal close to the Nyquist frequency. Keywords: sampling, A/D conversion, estimation, measurement MEASUREMENT VERIFICATION OF ESTIMATION METHOD FOR TIME ERRORS IN A TIME-INTERLEAVED A/D CONVERTER SYSTEM J. Elbornsson, K. FolkessonLinköping University Department of Electrical Engineering {jonas,kalfo}@isy.liu.se J.-E. EklundEricsson Microelectronics AB jan-erik.eklund@mic.ericsson.se ABSTRACT A previously presented method for estimation of time errors in time-interleaved A/D converter systems is here verified on measurements from a dual A/D converters system. The advantage of this estimation method, compared to other methods, is that it does not require any knowledge about the input signal. The estimation is most accurate for slowly varying input signals but the signal quality is improved even when the estimation is done for a sinusoidal signal close to the Nyquist frequency.
To significantly increase the sampling rate of an A/D converter (ADC), a time interleaved ADC system is a good option. The drawback of a time interleaved ADC system is that the ADCs are not exactly identical due to errors in the manufacturing process. This means that time, gain and offset mismatch errors are introduced in the ADC system. These errors cause non harmonic distortion in the sampled signal.One way to decrease the impact of the mismatch errors is to spread the distortion over a wider frequency range by randomizing the order in which the ADCs are used in the interleaved structure. In this paper we analyze how the spectrum is affected by mismatch errors in a randomly interleaved ADC system. We also discuss how the mismatch errors can be estimated. One way to decrease the impact of the mismatch errors is to spread the distortion over a wider frequency range by randomizing the order in which the ADCs are used in the interleaved structure. In this paper we analyze how the spectrum is affected by mismatch errors in a randomly interleaved ADC system. We also discuss how the mismatch errors can be estimated.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.