ETD

Archivio digitale delle tesi discusse presso l'Università di Pisa

Tesi etd-09072015-120927


Tipo di tesi
Tesi di laurea magistrale
Autore
GABRIELLI, GIOVANNI
URN
etd-09072015-120927
Titolo
Design of a CMOS chopper instrumentation amplifier with rail-to-rail input and output ranges
Dipartimento
INGEGNERIA DELL'INFORMAZIONE
Corso di studi
INGEGNERIA ELETTRONICA
Relatori
relatore Prof. Bruschi, Paolo
correlatore Prof. Piotto, Massimo
Parole chiave
  • instrumentation amplifier
  • current feedback
  • chopper
  • rail-to-rail
  • CMOS
  • sensor readout
Data inizio appello
25/09/2015
Consultabilità
Completa
Riassunto
This thesis deals with the design of a current feedback instrumentation amplifi er, optimized for the readout of thermal sensors. This topology stands out for its excellent CMRR and the predisposition to feature low frequency error reduction techniques. Versatility is a main target for this work: 1 kHz bandwidth and Rail-To-Rail input common mode range allow the readout of a wide variety of sensors.
Chopper modulation is used to reduce offset and flicker noise, achieving a 19 nV/sqrt(Hz) RTI noise density and a flicker corner frequency of less than 10 mHz. A low total output noise power is achieved as well, reaching an ENOB of 12 bits with less than 350 µA current consumption.
The peculiar issue for this architecture, that is gain error, is solved by means of Port Swapping technique, together with an input Common Mode Equalization. Chopped offset and Port Swapping ripple are completely fi ltered away by a third order Butterworth State Variable low pass fi lter, implemented with Gm-C integrators.
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