The present Master Thesis work, carried out at the Sensors and Detectors Laboratory of the Department of Electronics, Information and Bioengineering of Politecnico di Milano has the purpose of implementing a versatile setup for noise and temperature characterization of MEMS capacitive accelerometers on a shaker. The setup includes both the design and validation of the readoutelectronics as well as the conception and construction of the holding frame which will act as bridge between the board and the vibrating table. The electronic circuit must be compact and is carefully developed by selecting those discrete components whose behaviour is practically temperatureindependent while introducing the least possible noise to avoid disturbing the measurements. On the other hand, the mechanical support is built with Ergal to have a good ratio between weight and stiffness and thus avoid that low frequency modes of the setup may occur in the accelerometer bandwidth. Several measurements are conducted such as sensitivity, noise and offset temperature drift. Particular emphasis has been placed on studying the possible causes which make the output voltage vary in temperature by elaborating a Matlab algorithm to detect also the intrinsic MEMS drift. With the proposed technique, offset drifts of the electronics can be identified, leaving visible the pure MEMS drift, with identified values as low as 20ug/K.
Il seguente lavoro è stato svolto presso il laboratorio di Sensors and Detectors del Dipartimento di Electronica, Informazione, Bioingegneria del Politecnico di Milano. L’obiettivo principale di questa tesi è lo sviluppo di un sistema di caratterizzazione versatile per l’analisi del rumore intrinseco e del comporamento in temperatura di accelerometri MEMS. Questo studio comprende sia l’ideazione e la validazione dell’elettronica di lettura dei dispositivi, che la progettazione di un supporto meccanico necessario al fine di accoppiare la scheda di lettura alla strumentrazione usata per le prove di natura meccanica. L’elettronica è stata sviluppata con componeti discreti e concepita con il fine di minimizzare dimensioni del circuito, dipendenza dalla temperatura e rumore elettronico di lettura. Per quanto riguarda il supporto meccanico, particolare attenzione è stata data alla scelta del materiale; una lega d’alluminio (Ergal), che presenta un alto modulo di elasticità ad un peso specifico ridotto, è stata scelta al fine di evitare modi di risonanza del supporto all’interno della banda di caratterizzazione dei dispoistivi. In seguito all’introduzione del sistema di caratterizzazione, vengono presentate misure di sensitività, rumore e drift dell’offset in temperatura. Riguardo questo ultimo aspetto, particolare atttenzione è stata data allo studio delle cause di questo fenomeno e allo sviluppo di un algoritmo Matlab per estrarre i valori di drift intrinseco del dispositivo. Grazie a questo metodo, sono stati osservati valori di drift fino ad un minimo di 20ug/K
Design and qualification of a versatile setup for noise and temperature characterization of MEMS capacitive accelerometers
FERNÁNDEZ LÓPEZ-REY, VÍCTOR
2016/2017
Abstract
The present Master Thesis work, carried out at the Sensors and Detectors Laboratory of the Department of Electronics, Information and Bioengineering of Politecnico di Milano has the purpose of implementing a versatile setup for noise and temperature characterization of MEMS capacitive accelerometers on a shaker. The setup includes both the design and validation of the readoutelectronics as well as the conception and construction of the holding frame which will act as bridge between the board and the vibrating table. The electronic circuit must be compact and is carefully developed by selecting those discrete components whose behaviour is practically temperatureindependent while introducing the least possible noise to avoid disturbing the measurements. On the other hand, the mechanical support is built with Ergal to have a good ratio between weight and stiffness and thus avoid that low frequency modes of the setup may occur in the accelerometer bandwidth. Several measurements are conducted such as sensitivity, noise and offset temperature drift. Particular emphasis has been placed on studying the possible causes which make the output voltage vary in temperature by elaborating a Matlab algorithm to detect also the intrinsic MEMS drift. With the proposed technique, offset drifts of the electronics can be identified, leaving visible the pure MEMS drift, with identified values as low as 20ug/K.File | Dimensione | Formato | |
---|---|---|---|
TesiVictor.pdf
accessibile in internet per tutti
Descrizione: DESIGN AND QUALIFICATION OF A VERSATILE SETUP FOR NOISE AND TEMPERATURE CHARACTERIZATION OF MEMS CAPACITIVE ACCELEROMETERS
Dimensione
4.26 MB
Formato
Adobe PDF
|
4.26 MB | Adobe PDF | Visualizza/Apri |
I documenti in POLITesi sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
https://hdl.handle.net/10589/135108