Input-Dependent Integral Nonlinearity Modeling for Pipelined Analog-Digital Converters

• Published in: IEEE transactions on instrumentation and measurement 2010-10, Vol.59 (10), p.2609-2620
• Main Authors: Medawar, Samer, Händel, Peter, Björsell, Niclas, Jansson, Magnus
• Format: Article
• Language: English
• Subjects: Analog-digital conversion; Analogdigital conversion; Bandwidth; Converters; Dynamics; Electrical engineering, electronics and photonics; Elektroteknik, elektronik och fotonik; integral nonlinearity (INL); Integrals; least-squares methods; Methodology; Nonlinearity; parametric modeling; Parametric statistics; Pipelines; postcorrection; Radio frequencies; Radio frequency; RF signals; Running; Sampling methods; segmentation; Signal resolution; Stimuli; Studies; TECHNOLOGY; TEKNIKVETENSKAP; Voltage; Wideband
• ISSN: 0018-9456; 1557-9662; 1557-9662
• DOI: 10.1109/TIM.2010.2045551

Integral nonlinearity (INL) for pipelined analog-digital converters (ADCs) operating at RF is measured and characterized. A parametric model for the INL of pipelined ADCs is proposed, and the corresponding least-squares problem is formulated and solved. The INL is modeled both with respect to the converter output code and the frequency stimuli, which is dynamic modeling. The INL model contains a static and a dynamic part. The former comprises two 1-D terms in ADC code that are a sequence of zero-centered linear segments and a polynomial term. The 2-D dynamic part consists of a set of polynomials whose parameters are dependent on the ADC input stimuli. The INL modeling methodology is applied to simulated and experimental data from a 12-bit commercial ADC running at 210 mega samples per second. It is demonstrated that the developed methodology is an efficient way to capture the INL of nowadays ADCs running at RF, and it is believed that the methodology is powerful for INL-based ADC postcorrection in wideband applications.