Simon Hainz

Integrated photodiodes in standard BiCMOS technology

Photodiode structures were integrated in a low cost 0.5 μm silicon BiCMOS process using standard process flow without any technology modification. Rise times of 1.3ns and 1.4ns were measured for wavelengths λ of 660nm and 780nm with a responsivity of 0.23 A/W and 0.14 A/W, respectively. Photodiodes with a high responsivity of 0.42 A/W are reaching a risetime of 4ns for λ = 780nm. Comparable low values for the risetime at 780nm are reported in the literature for integrated photodiodes in standard silicon technologies only with a modification of the epitaxial substrate material. So this photodiodes are suitable for a wide variety of low-cost high-speed optical sensor applications, for optical fiber communication and fiber in home applications.

Compensation of Angular Errors Using Decision Feedback Equalizer Approach

Speed and position measurements of rotating shafts are very important in the field of mechanical engineering. In automotive applications, magnetic field sensors for such measurements (camshaft, crankshaft, anti-lock braking system, windshield wiper, etc.) have the largest market share of all sensor types. Camshaft applications are challenging due to their requirements on high angular accuracy under harsh environmental conditions. Due to mounting and packaging tolerances, the magnetic field at the sensors position varies, resulting in angular measurement errors for sensor concepts in use today. Mounting and packaging tolerances cannot be avoided; however, they can be compensated by a new filter structure which is described in this paper. The decision feedback equalizer (DFE) - known from digital communication - was analyzed and modified for the use in angular measurement applications. A new filter structure, using data prediction and an adaptive algorithm based on a physical model, is proposed. This filter calculates and compensates angular errors caused by mounting and packaging tolerances.

GMR-basierter, störfeldrobuster Kurbelwellensensor für Hybridfahrzeuge

Die steigende Anzahl von Aktuatoren und Sensoren in modernen Verbrennungsmotoren, gepaart mit einer steigenden Anzahl von Hybridfahrzeugen, erfordern eine neue Generation von robusten Sensoren. Induktives Laden von Akkumulatoren aus Elektrofahrzeugen als auch hoch performante Elektroantriebe erzeugen magnetische Felder, welche magnetische Sensoren beeinflussen. Zusatzliche magnetisch sensitive Sonden sind notwendig, um das Nutzsignal vom Storsignal der benachbarten Applikation, zum Beispiel der elektrische Antrieb eines Nockenwellen-Phasenstellers, zu unterscheiden. Zur selben Zeit besteht die Notwendigkeit weiterer Verbesserungen am Sensorkonzept wie zum Beispiel Temperaturkompensation oder digitale Algorithmen. Die hohe Empfindlichkeit von xMR-Technologie (Magneto-Resistance, x steht fur die moglichen Auspragungen A (Anisotrop), G (Giant) oder T (Tunnel)) ermoglicht die Verwendung von billigen Ferritmagneten, um die Systemkosten zu reduzieren.