A/D Converters

Our research in analog-to-digital converters (ADCs) focuses on different topics. Various types of Sigma-Delta modulators as well as high-resolution SAR ADCs are investigated.

For Sigma-Delta modulators, we cover the description and modeling of non-ideal behaviors. Moreover, the development of new design methodologies is at the center of interest. Both innovative architectures and improvement of established techniques are explored. Our work analyzes and designs Sigma-Delta modulators for wireless receivers as well as biomedical implants.

Furthermore, we develop new concepts for high resolution SAR ADCs. The research targets to advance the state-of-the-art with novel architectures that provide low power, low cost and at the same time highly efficient Nyquist rate ADCs.


High-Resolution, Efficient Incremental Sigma-Delta Modulators

M. Mokhtar: Sigma-Delta (ΣΔ) ADCs are suitable for various applications, due to its oversampling and noise-shaping behavior, thus high resolutions can be achieved independent on the matching accuracy of the analog components. For multiplexed applications, where an ADC is used to digitize the input coming from multi-channels ... [more]

High-Resolution Incremental Sigma Delta ADCs for Biomedical Signals

P. Vogelmann:  In the past few years, an increased interest in biomedical implants like neural recorders is noticeable as measured by the number of publications. These devices are integrated circuits (ICs) that comprise more and more functionality which increases their versatility and importance in medical research...  [more]

Blocker and Jitter-Tolerant Continuous-Time Sigma-Delta ADCs

J. Chi: Continuous-time (CT) Sigma-Delta ADCs are a promising candidate for high-speed receiver applications, such as software-defined radio (SDR), due to its inherent anti-aliasing and signal filtering, potential lower power consumption because of less stringent requirements on Op-Amps, and easy reconfigurability ... [ more]

Online Tool for Rapid Continuous-Time ΣΔ Modulator Design

J. Wagner: ΣΔ A/D converters are the state of the art for many different applications. The basis for this type of A/D converter is the ΣΔ modulator. For a long time, discrete-time (DT) ΣΔ modulators dominated as their design techniques could easily be adopted to ensured high performance... [ more]

High resolution SAR ADC employing Sigma Delta DACs

Y. Luo: ADCs are essential building blocks for almost all electronic systems, they represent the key element that allows the digital representation of any electrical signal located in the analog domain, and hence these by-nature analog signals could be processed by the latest sophisticated digital processing units only after well A/D conversion in the ADCs ... [ more]

Ultra-low Power, Wide Bandwidth Continuous-time Sigma Delta Analog to Digital Converter Design

A. Abdelaal, M. Pietzko: Continues time delta sigma modulators (CTDS) have recently become the key device for broadband wireless and wireline communication.  Due to there built in anti-aliasing filter and the ability to have relaxed sampling requirements the CTDS modulators are preferred over there discrete time counterparts ... [more]