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ABSTRACT: We have developed an optical laser probe for the measurement of absolute surface temperature changes in integrated circuits. The experimental method is based upon thermoreflectance, which is the change in reflectance due to surface temperature changes of the device. A laser beam is focused upon a small spot of an operating circuit. The reflected intensity is recorded upon a photodiode in synchronism with the circuit periodic excitation signal. We calibrated the device by developing a simple analytical model to calculate the surface temperature behaviour of a silicon resistive structure we tested. The value we derived for the relative reflectance temperature coefficient of silicon is in excellent agreement with the value from the literature. The results show the laser probe to be a fast surface thermometer (DC to 10 MHz), with excellent lateral resolution (1 μm), with high sensitivity (10−3°C) and large dynamics (ΔT: 102 to 10−3°C).
Quality and Reliability Engineering 03/2007; 9(4):303 - 308. · 0.70 Impact Factor
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ABSTRACT: The technique of ‘scanning’ with a laser beam permits a localization of latch-up sites in CMOS technology with a resolution less than one micron. Electrical simulations correlated to experimental curves of ‘supply current’ versus ‘photo-induced current’ offer a good evaluation of the predominant parameters of the parasitic structure.
Quality and Reliability Engineering 03/2007; 9(6):477 - 482. · 0.70 Impact Factor
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ABSTRACT: Functional tests with an electrical tester have revealed defects in an ASIC. Results analysis leads to incriminating different areas of the layout. A laser beam tester localizes the logic operator responsible for the dysfunction observed with the electrical tester.
Quality and Reliability Engineering 01/2007; 8(3):213 - 217. · 0.70 Impact Factor
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ABSTRACT: A new current mode synthesis method for dynamic translinear filters is proposed. As a design example, we have considered an ultra-low power second order filter working in audio frequency range, for hearing aids application, and using subthreshold MOS devices. It has a nominal supply voltage of 1.2 V and works down to 1 Volt. It has a power consumption of 5 W. The filter cut-off frequency and its Q factor can be tuned respectively from 600 Hz to 13 kHz and from 0.6 to 1.1. Mismatch problems are investigated on the circuit level and an on-chip compensation method is proposed.
Analog Integrated Circuits and Signal Processing 02/2000; 22(2):221-229. · 0.59 Impact Factor
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ABSTRACT: An ultra-low voltage relaxation oscillator providing output frequency up to 300 MHz is presented. Theoretical calculations as well as experimental measurements are discussed. A tuning range extending from a few megahertz to 305 MHz while consuming less than 1.4 mA has been measured on a 0.8 µm BiCMOS prototype. This circuit yields a phase noise of -78.5 dBc/Hz, a 500 ppm/mV sensitivity to power supply variation and a -600 ppm/°C temperature dependency.
Solid-State Circuits Conference, 1998. ESSCIRC '98. Proceedings of the 24th European; 10/1998
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ABSTRACT: A new current mode synthesis method for dynamic translinear
filters is proposed. As a design example, we have considered an
ultra-low power second order filter working in audio frequency range,
for hearing aids application, and using subthreshold MOS devices. It has
a nominal supply voltage of 1.2 V and works down to 1 V. The total power
consumption is about 5 μW. The filter cut-off frequency and its Q
factor can be tuned respectively from 600 Hz to 13 kHz and from 0.6 to
1.1. Mismatch problems are investigated on the circuit level and an
on-chip compensation method is proposed
Electronics, Circuits and Systems, 1998 IEEE International Conference on; 02/1998
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ABSTRACT: A CMOS built-in current sensor is proposed. It is dedicated to
mixed signal circuits power supply current monitoring. It takes
advantage of a parasitic resistor, so its implementation is very
transparent. Measurement results of a manufactured test chip highlight
the behaviors of the sensor in terms of linearity, speed and noise
IDDQ Testing, 1997. Digest of Papers., IEEE International Workshop on; 12/1997
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ABSTRACT: This paper presents a high-frequency current-controlled relaxation oscillator designed for ultra-low voltage supply (0.9 V). The choosen relaxation oscillator topology provides both high frequency and low noise characteristic. Simulated results are verified by measurements on a full-custom integrated circuit. The tuning range extends from 1 to 180 MHz with supply current limited to 1.1 mA. At a 200 kHz off set from the oscillator frequency, the measured phase noise is-89 dBc/Hz.
Solid-State Circuits Conference, 1997. ESSCIRC '97. Proceedings of the 23rd European; 10/1997
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ABSTRACT: In this article, a voltage/frequency converter with dynamic offset
trimming is presented. This converter is simple in structure, good in
accuracy and low in power consumption. It is realized in a 1.2 μ
BiCMOS technology. The result of test shows that an offset reduction as
smaller as 600 μV can be obtained
Analog and Mixed IC Design, 1997. Proceedings., 1997 2nd IEEE-CAS Region 8 Workshop on; 10/1997
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ABSTRACT: Teaching analog electronics leads us to set up a complete analog integrated circuit design flow to allow students to detail the main aspects of designer's tasks. In our case we propose the following design flow: circuit design and simulation, circuit integration by customizing prediffused array, die bonding and testing of the final circuit. All these steps require classical equipment except customizing the array which is made by a laser beam direct writing system
Microelectronic Systems Education, 1997. MSE '97. Proceedings., 1997 IEEE International Conference on; 08/1997
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ABSTRACT: This paper presents a current reference achieving excellent
behavior with regards to its temperature stability, which is able to
operate under ultra-low voltage supply conditions (down to 0.9 V).
Simulated results are verified by measurements on a full-custom
integrated circuit. The latter includes current reference of roughly 42
μA, and measurement depicts a temperature coefficient (TC) down to
120 ppm/°C without any adjustment, upon the military range. Due to
the ratiometric property, this reference is highly reproducible. In
addition, this current reference was designed to be power supply
independent
Circuits and Systems, 1997. ISCAS '97., Proceedings of 1997 IEEE International Symposium on; 07/1997
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ABSTRACT: Our paper deals with an electronic full-custom circuit designed to
accurately model the calcium dependence function of biological neurons.
This ASIC is one in a set of modules dedicated for the analog modeling
of neural networks and more specifically their use in real-time running
hybrid experiments. Measurements and behaviors of modeled neurons are
presented in various configurations and compared with theoretical
predictions
Neural Networks,1997., International Conference on; 07/1997
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ABSTRACT: This paper carried out a new design of head sized sensor arrays
with a simple delay-and-sum beamforming which provides useful amounts of
directivity index with sufficient robustness to errors. A
frequency-independent sidelobe reduction is proposed to achieve optimal
frequency characteristics. In order to obtain this control, a principle
of combining multiple level of array structures is established. Results
are presented for spherically isotropic noise. It is found that good
performance can be obtained for a head sized array by combining multiple
level structures with simple delay and sum beamformer
Acoustics, Speech, and Signal Processing, 1997. ICASSP-97., 1997 IEEE International Conference on; 05/1997 · 4.63 Impact Factor
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ABSTRACT: This paper presents two new strain gauge bridge-to-pulse position
modulation (PPM) converters. They have been developed in 2-μm BiCMOS
technology. The first one uses a chopper amplifier and a voltage-to-time
converter associated in a feedback loop. This topology mainly exhibits
an automatic offset cancellation capability, a ratiometric transfer
function, and 10-b accuracy. The second one is a voltage-to-frequency
converter using the switched-capacitor (SC) technique. It is an
optimized version in terms of size minimization and noise rejection.
Furthermore, a special RF transmitter has been designed in order to send
the data from an intracorporal sensing and conditioning circuitry to an
external computer dedicated to data analysis. Moreover, these converters
are insensitive to offset drifts and are well suited for long term
monitoring of orthopedic implants used for the treatment of bone
fractures
IEEE Journal of Solid-State Circuits 04/1997; · 3.23 Impact Factor
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ABSTRACT: A CMOS built-in current sensor dedicated to power supply current
monitoring is proposed, which takes advantage of the parasitic resistor
attached to an interconnection layer. Simulation results highlight the
behaviour of the sensor in terms of speed, linearity and noise. Process
dependencies are taken into account
Electronics Letters 03/1997; · 0.96 Impact Factor
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ABSTRACT: The aim is the design of an I<sub>DDX</sub> sensor integrated within the Circuit Under Test (CUT). Its function is transparent because its power consumption does not affect the behaviour of the CUT. This transducer is fast, accurate, linear and small for its possible duplication in the CUT. It does not need a specific power supply, and this power supply should be cut to inhibit the I<sub>DD</sub> function whenever the CUT is in normal use. In response to a Heaveside signal, a rise time lower than 1 ns was chosen. The desired I<sub>DD</sub> range is 0 to 10 mA. This work is not a new approach of fault detection but shows the application of new means for static and dynamic measurements of I<sub>DD</sub>
IDDQ Testing, 1996., IEEE International Workshop on; 11/1996
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ABSTRACT: The use of a laser beam is a well-known technique to trigger
latchup parasitic structures in ICs. Numerical analyses of this
phenomenon are brought into play to study its sensitivity when a
continuous wave laser as well as pulsed lasers are used. The impact
location is also studied to demonstrate that different mechanisms are
involved in the triggering phase of latchup. The structure is more
sensitive to blue light when it is directed over the well-substrate
junction, while it is more sensitive to infrared light elsewhere. When
using a CW laser, curves giving the power supply current versus the
photo-induced current provide direct information on the parameters of
the parasitic structure
IEEE Transactions on Nuclear Science 07/1996; · 1.45 Impact Factor
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ABSTRACT: A new strain gage bridge to PPM (Pulse Position Modulation)
converter has been developed. It consists of a chopper amplifier and a
voltage to time converter associated in a feed-back loop. This topology
exhibits mainly an automatic offset cancellation capability, a
ratiometric transfer function and an accuracy of 10 bits. Therefore,
this converter is insensitive to offset drifts, and is well suited for
long term monitoring of orthopedic implants
Custom Integrated Circuits Conference, 1996., Proceedings of the IEEE 1996; 06/1996
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ABSTRACT: This paper describes a new methodology to extract active doping
profiles in a bipolar technological process. Simulated device
characteristics coming from a physical simulator are matched to
electrical measurements following a straightforward procedure. The
influence of doping profile models, physical and statistical models and
how to drive convenient experiments on the device under test is
discussed
Microelectronic Test Structures, 1996. ICMTS 1996. Proceedings. 1996 IEEE International Conference on; 04/1996
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ABSTRACT: This paper presents an analog design of a biologically inspired
neuron model: the conductance-based Hodgkin-Huxley formalism. After a
description of the model equations set, the corresponding subcircuits
are detailed. ASICs were fabricated in a 2 μm BiCMOS technology, and
have a block structure allowing the constitution of complex cells or
small networks. As an application, numerical and analog computations of
the action potentials are compared, and the effects of some model
parameters modifications are shown
Microelectronics for Neural Networks, 1996., Proceedings of Fifth International Conference on; 03/1996
