الفهرس 
Motivation.
2 Overview on MEMS Inertial Sensors and Interface CircuiOnly 14 pages are availabe for public view
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Abstract
This thesis present.’> analysis of the non-idealities in the feedback path of Ell Force-Feedback
M EMS inertial sensors as well as the circuit implcmentntion of the reference voltage for the
feedback. A high-performance MEMS accelerometer sensing system is used as a test-vehicle for
the presented analysis and design.
On the system level, analysis is performed on the effect of clock-jitter in the feedback path
on the signal-to-noise (SNR) ratio of the accelerometer system. The effect of both white jitter
and cumulative jitter are investigated. ]t is shown that cumulative jitter has negligible effect on
the SNR of high performance Ell Force-Feedback systems. On the other hand, it is shown that
white jitter can severely limit the SNR. of Ell Force-Feedback systems. Analytical relations are
derived for the effect of Jitter on SNR..
Analysis is also performed on the effect of the reference voltage noise, in the feedback path,
on the SNR of Ell Force-Feedback systems. Analytical relations are derived that describe the
effect of the reference noise on t.be acbievebale SNR. It is shown that the reference noise does
not limit the sensitivity of the system; it only affects the maximum achievable SNR. It is also
shown that the maximum SNR will be independent on the signal level; it will only depend on the
Reference Voltage-to-Reference voltage noise ratio.
Based on the system-level analysis. spec; arc derived for the voltage reference for achieving
a 110<18 SNR 01] system level. The various reference-voltage technologies are overviewod, and
bandgap technology is chosen. Circuit implementation of a low-noise bandgap reference circuit is
then performed ou a 5iGe O.35/Lm BiGMOS technology. Three different topologies of the bandgap
voltage are implemented and simulated.
The I’” bandgap circuit is a convcntioual CMOS implementation of the bandgap circuit
with a 1Ht order temperature compensation. Chopping is used to overcome l/f noise. Circuit
implementation is made to enable trimming the reference for minimum temperature coefficient
ill CI\.~eof process variations. This reference achieves a total integrated noise of Ip.V from 1 mHz
to LOOHz with a reference voltage value of 1.2V.
The 2”d circuit is also a l·ot order compensated bandgap thnt makes UfIC of the opn bipolars
nvnilablc ill the technology to achieve the low-flicker noise target. The circuit is capable ogenerating a 1.2V and a 2.4V references aimultanoously IUId achieves n total integrated noise of
Ics.~than 2p.V (in the ImH7rlOOHz range] on the 2.4V reference.
In the 3rd circuit, n new higher-order temperature oompcnserion technique is proposed and
implemented. The circuit achieves a O.55ppm;oC temperature coefficient over the -40°C-125°C
temperature range. The integrated noise, however, is lUI order of magnitude larger thlUl the other
two implementations