Jürgen Oehm

Mismatch Modeling and Simulation—A Comprehensive Approach

This article describes a comprehensive approach to mismatch simulation and modeling as needed for integrated circuit design. Local device mismatch as well as global process variations and parameter correlations are regarded. A method for mismatch modeling based on spatial frequencies is described, which enables to overcome insufficiencies of the first order models. Measurement results are presented to demonstrate the achieved modeling precision. All models and methods mentioned here are commercially available in the simulation tool GAME (General Analysis of Mismatch Effects) which is used in the semiconductor industry since 1998.

A Hardware-Based Countermeasure to Reduce Side-Channel Leakage: Design, Implementation, and Evaluation

Side-channel attacks are one of the major concerns for security-enabled applications as they make use of information leaked by the physical implementation of the underlying cryptographic algorithm. Hence, reducing the side-channel leakage of the circuits realizing the cryptographic primitives is amongst the main goals of circuit designers. In this paper, we present a novel circuit concept, which decouples the main power supply from an internal power supply that is used to drive a single logic gate. The decoupling is done with the help of buffering capacitances integrated into semiconductor. We also introduce-compared to the previously known schemes-an improved decoupling circuit which reduces the crosstalk from the internal to the external power supply. The result of practical side-channel evaluation on a prototype chip fabricated in a 150nm CMOS technology shows a high potential of our proposed technique to reduce the side-channel leakages.

Light Source Position Measurement Technique Applicable in SOI Technology

Integrated optical sensors make use of a p-n-junction for light intensity detection, typically. Because of the costs, additional optical components are not available in standard integration processes. Therefore, in higher level optical sensors extra optical components are not part of an integration. In this paper a concept for integration is proposed, which especially allows to measure the angles of a far distance light source relative to the surface of the chip and the coordinate system of the integrated structure. The invention makes use of the stack topology and the light opacity of metal layers in the monolithic integration, the light translucency of , and the electrical light sensitivity of diodes. Because of perfect device isolation the implementation can be done most advantageously in SOI CMOS technology. With minor modifications it is applicable in other integration technologies as well. But leakage currents and device mismatching will limit the obtainable performance additionally.

High precision optical angle measuring method applicable in standard CMOS technology

In this paper a new concept for high precision angle measurement in standard CMOS technology is presented. In comparison to previous works, the complexness of the sensor topology is strongly reduced, the measuring range and the accuracy are significantly increased. The wavelength and the light intensity have a negligible influence on the accuracy of the sensor. In contrast to the previous concept, where SOI technology is mandatory, this new sensor concept can also be realised using standard CMOS technology.

Statistical Analysis and Optimization of a Bandgap Reference for VLSI Applications

Voltage and current references are widely needed for all kinds of integrated circuits, as most applications require temperature-independent references with a high reproducibility in mass production. For this purpose normally bandgap references are used. Though it is a common task to set up an application specific bandgap circuit, handling of the statistical design aspects is often not a standardized step in the design flow. This article describes some of the steps that were taken during the design of a bandgap reference for a given VLSI application. All statistical simulations were carried out with the simulation tool GAME (General Analysis of Mismatch Effects) which is used at Infineon/Düsseldorf since 1999.

Sensor applications in charging stations for electric vehicles

A safe and secure charging process for electric vehicles is a prerequisite for an increasing share of electromobility in the traffic sector. A sensor system for a single phase charging station is developed that fulfils different requirements. These application requirements are evaluated and the selected special current and voltage sensors are explained. Several simulations for the signal processing are presented that serve as a basis for the individual decision regarding the needed data rate and precision for the different application requirements.

A CMOS 16k microelectrode array as docking platform for autonomous microsystems

A microelectrode array (MEA) system based on an active pixel architecture is presented, which has been fabricated in 180nm CMOS technology, featuring 16384 active pixels (36×36×m2). Each pixel consists of 4 electrodes (each 12×12μm2): two (connected together) for actuating and two for differential sensing. The pixels are arranged in a square grid of 4.6×4.6mm2. Schematic and layout of the MEA were generated by a SKILL script. The MEA is designed as a docking platform for charging and communicating with autonomous microsystems, called lablets, as well as combinatorial electrochemistry. Experiments in aqueous electrolyte solutions confirm the functionality of the MEA to fulfill the requirements of a flexible configuration of the pixels and the possibility of charging microsystems in a solution.

A measurement system for electric car charging stations utilising a FPGA board for flexibility in configuration

In this paper we present a prototype of a measurement system for an electric car charging station, which provides much more than only battery charging. In addition to the core tasks, namely to measure the amount of transferred energy, and to organise the billing with the provider, a charging station must satisfy numerous other requirements. These include e.g. several safety aspects like the communication with the car, detection of electrical faults, and an ensuring for secure payments. The digital core units of the electric car charging station prototype have been implemented on an FPGA board. The FPGA platform was chosen in order to keep the prototype development process as flexible as possible. This paper will focus on such aspects, where in particular flexibility during the development phase was required.

A measuring method for high precision optical angle detection with no interference of ambient light

In former developed systems, high precision measuring of the angle of incidence of a light source can be obtained only in surroundings without ambient light. In this paper an enhanced method based on a previous system is presented. This method additionally allows precise measurements in environments with any ambient light conditions. So high precision angle measuring in industrial standard surroundings is not critical anymore.

Sensor data fusion with MPSoCSim in the context of electric vehicle charging stations

This paper presents a platform for evaluating sensor data fusion algorithms based on a Network-on-Chip (NoC). The NoC is simulated by MPSoCSim that contains an ARM and several MicroBlaze processors. The approach is evaluated in an automotive context. Charging stations for electric vehicles consist of expensive sensors, as the energy measurement system is an important part used for billing purposes, for safety of the charging process and for security. The sensors, that are usually used, are special made solutions, which are thermally stable and highly accurate. The NoC infrastructure presented in this paper results in a new method for sensor data fusion, which decreases costs by using inexpensive sensor units. The target of the sensor data fusion approach is to replace expensive sensors with many inexpensive one without loosing accuracy. The presented simulation platform allows an easy exchange of sensor models and sensor data fusion algorithms. Complex algorithms can furthermore be transferred to programmable FPGA logic, which allows the simultaneous processing of sensor data.