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Electronic design automation approaches can roughly be divided into optimizers and procedures. While the former have enabled highly automated synthesis flows for digital integrated circuits, the latter play a vital (but mostly underestimated role) in the analog domain. This paper describes both automation strategies in comparison, identifying two fundamentally different automation paradigms that reflect the two basic design practices known as “top-down” and “bottom-up”. Then, with a focus on the latter, the history of procedural approaches is traced from their
early beginnings until today’s evolvements and future prospects to underline their practical importance and to accentuate their scientific value, both in itself and in the overall context of EDA.
Einpaarige Verkabelungssysteme gewinnen aufgrund des Internets der Dinge und aufgrund deren Einsatz im Automobil- bzw. Industriebereich zunehmend an Bedeutung. Im Rahmen dieser Arbeit wird gezeigt, wie bei der Übertragung über ein einpaariges Kabel die Bitrate bei gleichbleibender Übertragungsbandbreite durch Nutzung des Phantomkreises erhöht werden kann. Als Übertragungsverfahren kommt jeweils eine 16-stufige Pulsamplitudenmodulation zum Einsatz. Die Ergebnisse werden durch Augendiagramme qualitativ und durch die Messung der Symbolfehler bzw. der Bitfehler quantitativ untersucht.
Mit der Überarbeitung der DIN EN 50173 (VDE 0800-173) Serie, wurden unter anderem die optischen Übertragungsstreckenklassen ersatzlos gestrichen. Um die so entstandene Lücke zu schließen, hat das deutsche Gremium DKE GUK 715.3 „Informationstechnische Verkabelung von Gebäudekomplexen“ neue Klassen erarbeitet, die in der DIN VDE 0800- 173-100 „Klassifizierung von Lichtwellenleiter-Übertragungsstrecken“ im Juni 2019 veröffentlicht wurden. Die Norm klassifiziert Lichtwellenleiter Übertragungsstrecken für anwendungsneutrale Kommunikationskabelanlagen nach DIN EN 50173-1.
Sie dient Benutzern, eine breite Palette von Anwendungen zu ermöglichen, die Auswahl des Verkabelungssystems zu erleichtern, eine zukunftssichere Klassifizierung von LWL-Verkabelungen zu generieren und dazu, Systemanforderungen zu beschreiben.
Die in der Norm definierten Klassen beschreiben die Anforderungen an die Übertragungsstrecken und basieren auf einer maximal zulässigen Einfügedämpfung in dB für maximale Übertragungsstreckenlängen, wobei zusätzlich das Bandbreitenlängenprodukt berücksichtigt wird.
Der Beitrag liefert einen Überblick über die Norm und zeigt Anwendungsbeispiele auf.
This paper presents an improvement in usability and integrity of simulation-based analog circuit sizing. Instead of using geometrical sizing parameters (width, length), a transformed design-space, consisting exclusively of electrical parameters (branch currents, efficiencies and speed) is utilized. This design-space is explored more efficiently by optimizers. Moreover, this design-space can be reduced without affecting the quality of the result. The method is illustrated on two application examples, a symmetrical and a miller operational amplifier. Sizing the circuits using the transformed design-space showed significant reduction in required circuit simulations (up to 11x faster), better convergence, without loss in quality.
The current paper proposes a design method for an active damping approach for LC output filters in a power stage for motor control with continuous output voltage. The power stage uses GaN-HEMTs and operates at switching frequencies in a range between 500 kHz and 1MHz. The active damping of the output filter is achieved here by a feedback of the filter inductor current using a high-pass structure. The paper discusses the impact of this feedback on the system behavior and proposes a design method.
Es wird gezeigt, wie bei Fernspeisung die Vorhersage der Erwärmung mit entsprechender Modellierung verbessert werden kann und wie der Einfluss von Material und Form des Kabelkanals die Erwärmung und das das Temperaturprofil des Bündels beeinflusst. Es wird auch vorgestellt, dass die erhöhte Erwärmung von Metallkabelkanälen auf die geringere Emissivität zurückzuführen ist und wie das verbessert werden kann.
Nowadays robust, energy-efficient multisensor microsystems often come with heavily restricted power budgets and the characteristic of remaining in certain states for a longer period of time. During this time frame there is no continuous clock signal required which gives the opportunity to suspend the clock until a new transition is requested. In this paper, we present a new topology for on-demand locally clocked finite state machines. The architecture combines a local adaptive clocking approach with synchronous and asynchronous components forming a quasi synchronous system. Using adaptive and local clocking comes with the advantages of reducing the power consumption while saving design effort when no global clock tree is needed. Combining synchronous and asynchronous components is beneficial compared to previous fully asynchronous approaches concerning the design restrictions. The developed topology is verified by the implementation and simulation of a temperature-ADC sensor system realized in a 180 nm process.
Usually battery chargers have two stages and DC charging current is considered to by necessary for a proper charging. To decrease the charger volume, a single stage LLC battery charger is investigated in this paper. PFC stage is eliminated, therefore no bulky capacitor is necessary any more, and battery is charged with a sinusoidal-like charging current. However, previous studies show that such a pulsating charging current has only minimal impact on battery life and efficiency. Design considerations of the resonant tank and optimal transformer design are presented. A 360W single stage LLC converter prototype for e-bike charger achieves a power factor of 0.98, efficiency of 0.93 and power density of 1,8kW/dm³.
Der vorliegende Beitrag zeigte die Anwendung eines Extended Kalman Filters für die Beurteilung des Verschleißzustandes von Rollenketten. Anders als in den üblicherweise eingesetzten signalbasierten Verfahren wurde damit ein modellbasierter Ansatz gewählt. Der Einsatz des Extended Kalman Filters ermöglicht die Schätzung von Parametern eines reduzierten Kettenmodells, das die Dynamik der einzigen Messgröße, nämlich des Drehmoments des antreibenden Motors näherungsweise nachbildet. Im Beitrag wurde dieses Verfahren auf Messdaten aus vier Dauerversuchen an Rollenketten eingesetzt und gezeigt, dass mit steigendem Verschleiß eine Änderung ausgewählter Modellparameter erfolgt.
Diese Vorgehensweise ist ein erster Ansatz, der durch weitere Forschungsarbeiten noch verbessert werden muss. In zukünftigen Forschungsarbeiten wird zusätzlich zur Parameterschätzung eine Prädiktion durchgeführt, um einen Schätzwert für die Restlebensdauer zu erhalten. Hierzu gibt es Ansätze in der Literatur, die auf das konkrete Problem angepasst werden müssen. Zudem muss die Modellierungssystematik so erweitert werden, dass Wissen über das Prozessverhalten in die Modellierung mit eingebracht wird, um die Aussagekraft der Ergebnisse sowie die Robustheit des Verfahrens bezüglich Betriebsparametern, Umgebungsbedingungen und Exemplarstreuungen zu verbessern.
The integration of renewable energy sources in single family homes is challenging. Advance knowledge of the demand of electrical energy, heat, and domestic hot water (DHW) is useful to schedule projectable devices like heat pumps. In this work, we consider demand time series for heat and DHW from 2018 for a single family home in Germany. We compare different forecasting methods to predict such demands for the next day. While the 1-day-back forecast method led to the prediction of heat demand, the N-day-average performed best for DHW demand when Unbiased Exponentially Moving Average (UEMA) is used with a memory of 2.5 days. This is surprising as these forecasting methods are very simple and do not leverage additional information sources such as weather forecasts.
Class Phi2 amplifier using GaN HEMTs at 13.56MHz with tuned transformer for wireless power transfer
(2022)
This paper discusses a design procedure of a wireless power transfer system at a RF switching frequency of 13.56MHz. The wireless power transfer amplifier uses GaN HEMTs in aClass phi2 topology and is designed in order to achieve high efficiency and high power density. A design method for the load over a certain bandwidth is presented for a transformer with its tuning network.
Power loss measurement of power electronic components and overall systems is sometimes difficult by use of electrical quantities and in few applications even not possible. The calorimetric power loss measurement is an established method to identify the overall system losses with a suitable accuracy. This paper presents a novel method with an open chamber calorimeter under accurate air mass flow, air pressure, humidity measurement and temperature control. The benefits are the approximately halved measurement time compared to established systems and the possibility to control the chamber temperature. So it is possible to measure the power losses at different ambient temperatures.
Switched reluctance motors are particularly attractive due to their simple structure. The control of this machine type requires the instants, to switch the currents in the motor phases in an appropriate sequence. These switching instants are determined either based on a position sensor, or on signals generated by a sensorless method. A very simple sensorless method uses the switching frequency of the hysteresis controllers used for phase current control. This paper first presents an automatic commissioning method for this sensorless method and second a startup procedure, thus enhancing this approach towards an application in industry.
The demonstration project Virtual Power Plant Neckar-Alb is constructing a Virtual Power Plant (VPP) demonstration site at the Reutlingen University campus. The VPP demonstrator integrates a heterogeneous set of distributed energy resources (DERs) which are connected to control the infrastructure and an energy management system. This paper describes the components and the architecture of the demonstrator and presents strategies for demonstration of multiple optimization and control systems with different control paradigms.
A procedural approach to automate the manual design process in analog integrated circuit design
(2018)
This paper presents a novel approach to automating the design of analog integrated circuits: (1) the Expert Design Plan (EDP), a procedural generator, and (2) the EDP Language, a high-level description language for writing an EDP. An EDP is a parameterizable, executable script, which reproduces a designer’s course of action when designing a circuit. Thus, an EDP formalizes the design expert’s knowledge-based strategy and makes it reusable. Since it is essential that an EDP represents a circuit designers’ way of thinking and working as close as possible, the designers themselves should be enabled to create the EDP. Therefore, our approach provides a input method through a domain-specific language called EDP Language (EDPL). Using this language is intuitive and requires no special training. In an exemplary implementation of our approach, a common-source amplifier is automatically sized using a set of only 10 instructions. Even in the first usage our EDP approach has appeared to be more efficient than the manual sizing process.
A novel gate driving approach to balance the transient current of parallel-connected GaN-HEMTs
(2018)
To enable higher current handling capability of GaN-based DC/DC converters, devices have to be used in parallel. However, their switching times differ, especially if their threshold voltages are not identical, which causes unbalanced device current. This paper focuses on the homogeneous distribution of turn-on switching losses of GaN-HEMTs connected in parallel. By applying a new gate driver concept, the transient current is distributed evenly. The effectiveness of this concept is demonstrated by double pulse measurements, for switching currents up to 45A and a voltage of 400V. A uniform current distribution is achieved, including a reduction of the turn-on losses by 50% compared to a conventional setup.