Design for
MOSIS Education Program (Research)
An iInstrumentation amplifier appliedy at oneto a
high sensitivity Piezoresistive
silicon pressure transducer with high
sensitivity.
Designed by - Márcio Bender, Grad student
Gustavo Giusti, Grad
student
Márcio Cherem Schneider, Professor
Institution - Federal
University of Santa Catarina
Electrical Engineering Department
Integrated Circuits Laboratory
Date of Submission: September 310, 2004
A Research Proposal for the MEP
Summary
To: MOSIS
Submitted
by: marciobm@eel.ufsc.br
Professor: Márcio Cherem Schneider, marcio@eel.ufsc.br
Affiliation: Integrated Circuits Laboratory, Department
of Electrical Engineering, Federal University of Santa Catarina.
(www.eel.ufsc.br/lci)
Project Title: An iInstrumentation amplifier appliedy at oneto a
high sensitivity pPiezoresistive silicon transducer with high sensitivity.
Fabrication Technology: TSMC 0.35
Objective: To dDesign an
of an amplification circuit for signalss
originating from a pressure sensor of
pressure.
Challenges: To provide a simple circuit
of pressure transducertion circuit of pressure using
restricted features of the input and output.
Expected Publications: Publication
ofish the results
in international conference proceedingss.
Simulation support:
Smash circuit simulator, Tanner tools.
Chip size: 1.5mm x 1.5mm
Test: Measurement of DC and AC characteristics.
Equipment: HP
4145.
Packaging: DIP-
40.
Overview
Exist There are
several types of sensory systems with an
output differential, for example,. One of the examples
this system area bridge configuration sensor in bridge configuration. For the conditioning
of the signalss
originating from these systems, it is necessary the
use of a circuits
amplification differential is required, as the instrumentation amplifier. In this our project
an instrumentation amplifier was developed destined in order to amplify the signalss
originating from the a high
sensitivity Ppiezoresistive
silicon die pressure sensor die with high sensitivity. The amplifier will amplify amplify
the sign of the sensor signal, conditioning it inside
ofwithin a tension range
specified by thean
A/D converter.
Project
Description
The amplification
circuit has the function of elevating increasing the level of the sign of the pressure
transducer signalof pressure to
adjust this signal to the scale of the
circuit A/D converter (next stage of the project).
Fig.
1.1 – Amplification Circuit
The gain of the circuit
gain is divided between the1st stage of amplification and theand 2nd stages
of amplification. The scale of values coming of the
pressure sensor of
pressure is from 0 to 111.,36mV.
The output voltage range is from 0.,3 to 2.,7V.
This exit output
scale should begin atin 0.,3V, due to thatsince, in order to to operate with safelyty,
the A/D converter should begin with the a tension of 0,.3V. As the power supply voltage of the
converter is of 3V, and the maximum value of output
voltage should be of 2,.7V.
1st
stage of amplification
The 1st stage of
amplification has the function of amplifying the signal differential, being also used as a buffer
for the incoming
sensor signal coming from
the sensorof the sensor.
The circuit
presents a certain tension gain with the objective of decreasing the gain in
the second stage, thereby decreasing therefore, the reason
among resistance of the
resistors of that stage. In way toorder to decrease the voltage
of common mode voltage, it was inserted in the circuit, two current
sources were incorporated into the circuit, doing with that the voltage
of common mode voltage is being reduced in this way, of to 2.,4V for 1.,5V.
2nd st
stage of amplification
The second stage of amplification
has the objective of amplifying the incoming signal coming of from the first stage of amplification,
eliminating the voltage in a common mode using an
differential amplifier to differences. When the pressure sensor of
pressure is in the balance position, the circuit should presentgive
the an output voltage of 0.,3V.
The operational amplifier was designprojected
according to the model of the OTA circuit OTA model - Miller, that presents
has a differential input differential and simple
output
simple, with frequency compensation.
Lay out
Fig. 1.2 – Lay out
Experimental
Results
To test the circuit we put a differential sign in the input of circuit. The scale of the sign is 0 to 112mV. The experimental gain is about 21.3 V/V.
Fig. 1.3 – Experimental Result
References
[1] A. F.
P. Van Putten, Electronic Measurement Systems, London: Institute of Phyisics, 1996.
[2] R. J.
Baker, H. W. Li, D. E. Boyce: CMOS Circuit Design, Layout and Simulation,
IEEE
Press, 1st ed, 1998.