complex mixed signal IC for Sensor signal conditioning designed by Fraunhofer IMS containing analog frontend, AD-converter, digital part and memory
© Fraunhofer IMS
sensor signal conditioning IC

Integrated Sensor Systems

For integrated sensors we develop all necessary electronic components from analog frontend to digital interfaces

Integrated Sensor Systems

Today, environmental parameters are recorded using complex systems that contain not only the actual sensor, but also a large number of other electronic components for further processing of the sensor signal. At Fraunhofer IMS, we are working on such integrated sensor systems with the aim of accommodating as many functions as possible close to the sensor in an integrated circuit. Due to the series production of microelectronics, integrated sensor systems can be designed at low cost and miniaturized for a variety of applications. Depending on the type of application, such systems comprise different functional groups ranging from simple signal amplification and the conversion of sensor signals into digital form up to neural networks for the recognition of features and patterns. Our development activities in the field of integrated sensor systems cover the following main areas:

Picture of Sensor Frontend IC
© Fraunhofer IMS
Sensor Frontend IC, contains analogue and digital components for the amplification and transmission of sensor signals

Sensor Frontends

Sensors often deliver very small, frequently non-linear electrical signals, which are also available in different forms as current, voltage or even as a change in resistance. The processing of the signals for usability at higher application levels is the task of the so-called "analog front-end" (AFE) circuits. Often, the small signals have to be amplified, and ideally the amplification factor is programmable. In some cases, sensor signals are also subject to a high offset, which must be compensated by the AFE to ensure an optimum dynamic range. Some sensors, e.g. resistance bridges, also require an electrical signal (current) that must be fed in to obtain a sensor signal (voltage). This is also the task of the AFE. In addition, more complicated methods such as autozero or chopper amplifiers are also used, for example to reduce low-frequency noise.

Increasingly, sensor data is being processed digitally in integrated sensor systems. Analog/digital converters are used as the interface between the analog and digital signal forms, and different methods are used depending on the requirements. For sensor signal processing, converters based on the SAR method (successive approximation) or sigma-delta converters have proved particularly useful.

Detailed information about the performance range for analog front ends can be found here.

Mixed Signal Design

Modern integrated sensor systems signal processing usually consist of analog and digital components. There are a large number of interactions between these circuit parts. For example, many analog components are digitally programmed to set gain factors, to enable or disable certain functions, or to perform calibration operations. The necessary processes are controlled by the digital part. The connection to the outside world is established via standard interfaces (SPI, RS485). Because of the closely interlocked development of analog and digital components, the term "mixed-signal design" has become established. What exactly is hidden behind this and which functions we realize here, you can find out here.

System-on-chip design

We speak of system-on-chip solutions when all tasks of a functionally delimited electronic system are realized on a single silicon chip, e.g. sensor and/or sensor readout circuitry, analog functions, computing power in the form of a microcontroller, memory and local clock generators. Advantages of SoC for integrated sensor systems are the small footprint, as well as the low power consumption compared to systems made of single components.

In System-on-Chip design, we at Fraunhofer IMS offer developments of both FPGA-based and customer-specific ASIC solutions. Among others, embedded microcontrollers such as the RISC-V implementation (RV32IMC) developed at Fraunhofer IMS are used. Specific instruction set extensions for the RISC-V have been created for the efficient solution of special tasks (e.g. artificial intelligence). Hardware accelerators allow the implementation of AI algorithms or encryption methods. More information can be found here.

High temperature electronics

Microelectronics is a key technology for a wide range of everyday products. However, when used in harsh environments, especially at high temperatures, conventional electronics quickly reach their limits and can only be operated reliably up to about 150 °C. Nevertheless, sensors and actuators in industrial processes, oil production or geothermal energy, for example, are also required and used at significantly higher temperatures. These are then usually constructed from purely passive components and the electronics are operated remotely outside the hot area, which requires additional installation space and reduces performance.

High-temperature electronics make it possible to process the signals of the sensors or actuators directly on site in a space-saving manner and with high signal quality in the hot area. For this purpose, Fraunhofer IMS has developed a high-temperature silicon-on-insulator (SOI) CMOS technology on the basis of which integrated high-temperature electronics can be realized. The minimum structure size of 0.35 µm and up to four metal layers allow the realization of compact integrated systems including small embedded microcontrollers.

The realization of integrated circuits for a temperature range up to 300 °C requires a good understanding of the temperature behavior of individual components as well as possible parasitic effects. Fraunhofer IMS has extensive know-how in design and realization of high-temperature integrated electronics for use in harsh environments, even at temperatures up to 300 °C.

We offer design support as well as the complete realization of your high temperature capable application specific IC (HT-ASIC) from conceptual design to pilot production. Detailed information about high temperature electronics can be found at.

High Temperature IC in a ceramic package suitable for high temperatures
© Fraunhofer IMS
High Temperature IC in a ceramic package suitable for high temperatures
integrated circuit containing micromechanical pressure sensor with amplifier electronics and AD-converter
© Fraunhofer IMS
Pressure Sensor IC

Integrated sensors

Some environmental parameters can be measured by sensors which can be realized directly on a silicon chip. This opens up the possibility of extremely small and efficient integrated sensor systems that can be used in places where this previously seemed unthinkable. This has opened up completely new possibilities in medical diagnostics, for example. Here, on the one hand, physical effects of the silicon itself are exploited, such as temperature dependence or piezoelectric interactions, but on the other hand, integrated sensors can also be created by micromechanical processing or by applying additional layers to the silicon substrate. The many possibilities this opens up range from micromechanical acceleration sensors to bioactive layers that can detect pathogens, for example.

For more information on the "Integrated Sensors" service offering, click here.

Neural networks

The increasing use of sensors provides a wealth of data ready for processing at higher application levels. Often it is not even necessary to transfer all raw data from sensor systems to the system level, but to recognize certain features in them. Neural networks are increasingly used to recognize or evaluate such features already in the raw data and to forward only significant information. In this way, a considerable reduction in the amount of data to be transmitted can be achieved.

At Fraunhofer IMS, we are researching neural networks that can be implemented highly efficiently on simple hardware platforms. The goal is to develop even more efficient sensor systems that already include a high level of signal interpretation.  

Further information on the topic of neural networks can be found here.

Our technologies - Innovations for your products

Sensor Frontends

These first signal processing stages in sensor systems amplify, filter and convert sensor signals into digital form

Mixed Signal Design

Complex electronic functions are increasingly realized through the closely interlocked design of analog and digital circuits

System-on-Chip-Design

In SoC design, complex systems with microcontroller, memory and extensive application-specific functions are developed

High Temperature Electronics

For applications with up to 300°C ambient temperature a special technology is available at Fraunhofer IMS

Integrated Sensors

Integrated sensors can be incorporated directly into a circuit design and enable miniaturized, efficient sensor systems

Neural Networks

Neural networks often allow highly efficient signal analysis directly at the location of the sensor system

Our technology areas - Our technologies for your development

Optical Systems

Comprises 3D-Sensors, High-Speed-Imaging, detection of extreme low light as well as scientific imaging.

Wireless and Transponder Systems

Incorporates the wireless acquisition of sensor and ID-data even in passive systems.

 

Smart Sensor Systems

Here you can get back to the overview page of the core competence Smart Sensor Systems (SSS).