Integrated circuits for MEMS
The development of integrated circuits to drive micro actuators and to process signals of micro sensors are the main topics in the research activities of the "microsystem electronics" working group at the Chair of Electronic Devices. The field of activity comprises:
- Design of integrated high voltage circuits for electrostatically driven micro actuators
- Characterization and modelling of high voltage micro technology devices
- Design of low power and low noise integrated circuits for signal editing of micro-mechanical sensor arrays
- Electrical characterization of microsystems
Competence in integrated circuit design of the working group starts from linear amplifier circuits with an electrical strength of several hundreds of volts up to low voltage signal processing circuits in switched-capacitor technique.
Examples of electrostatically driven micromechanical components with capacitive behavior referring to their terminals include micro mirrors rotating in one or two dimensions and transducers based on the piezoelectric effect. Front-end circuits which are used to control such microelements for various applications have to be smart power amplifiers with the ability to drive up to 1000 V. Simultaneously, the dynamical parameters that must be fulfilled will be high for several applications.
The working group has developed a switched-capacitor circuit to read out sensor arrays. Corruption introduced by crosstalk and noise represents an important problem in reading out signals from a micromechanical sensor array. To solve this problem, a set of broadband signals with special correlation properties is used to excite sensor elements individually. A correlator circuit uses a correlation of sensor array signals with excitation signals and produces an estimation of the physical quantity. We have implemented the whole circuit in fully differential switched-capacitor technique for 5 readout channels.
Prof. Horstmann (Chair Electronic Devices)