Influence of passive oscillator component variation on OBT sensitivity in OTAs
2018 IEEE 19th Latin-American Test Symposium (LATS), 2018
Oscillation based testing (OBT) relies on converting the Circuit Under Test (CUT) into an oscilla... more Oscillation based testing (OBT) relies on converting the Circuit Under Test (CUT) into an oscillator during the test phase by adding a feedback loop in order to provoke self-sustained oscillation which is monitored at an output. The monitored output frequency and amplitude has previously been shown found sensitive to variation in the OBT's passive feedback circuit, while the choice of oscillator topology was shown to influence the discrimination between faulty and non-faulty circuits in idealized circuits. In this work, we evaluate the influence of this variation on fault discrimination in three different OBT oscillator configurations for an operational transimpedance amplifier (OTA). It is found that a 100% variation in passive component value can effect variation in the discrimination of below 29%, or as much as 2900%, depending on the oscillator topology under nominal operation. We further subject a typical test case to Monte Carlo analysis, which indicates that fault discrimination is maintained despite process variation.
A 90% Efficient, 50MHz Buck Converter for Space Telecom Systems
Multi-abstraction models for accelerating the design of RF systems
This work describes a step-down DC/DC converter sized and simulated in a CMOS-65nm process. From ... more This work describes a step-down DC/DC converter sized and simulated in a CMOS-65nm process. From a 0.7V primary source obtained by energy-harvesting the circuit is able to deliver a regulated voltage supply of 0.5V. This circuit is employed to supply a complete RF system. Since the target application demands very low current consumption, the Pulse-Frequency Modulation switching technique (PFM) is used. This makes possible to increase the total efficiency of the converter and, consequently, to extend the lifetime of such RF system. Along with the presented step-down converter, an overview of the buck converter is given. Specifically details on the basic equations, principles of how it works and the different ways of operating the converter through the PWM or PFM modulations. In this work each block of the circuit is thought and designed taking into account the power consumption as a main constraint. Different test benches are shown for the different blocks and their simulations. For this ultra low power application, we were able to achieve an efficiency of 65% starting from a 0.7V source and using a PFM feedback control to obtain a stable output voltage of 0.5V
A very high frequency step-down DC/DC converter for spaceborne envelope-tracking SSPA
2014 IEEE MTT-S International Microwave Symposium (IMS2014), 2014
ABSTRACT An experimental VHF DC/DC converter aimed at envelope-tracking amplifiers for space appl... more ABSTRACT An experimental VHF DC/DC converter aimed at envelope-tracking amplifiers for space applications is presented. Based on Gallium Nitride components, it is capable of operating in the range of tens of watts, as required by on-board transmitters. When driven by a 50-MHz PWM signal, it reaches a peak efficiency of 91.6%. A detailed breakdown of the associated losses is reported in order to identify the contributions. Additional measurements at 67 MHz show a peak efficiency of 89.8%.
Ultra-low power RF front-end powered by energy harvesting (POHAR projet, Numéro de convention : 1410164)
This paper presents experimental results showing that the energy contained in beta radiation can ... more This paper presents experimental results showing that the energy contained in beta radiation can be harvested by using diodes. A single BPW34 photodiode generates around 12 pA dc, so enough to power integrated analog blocks.
Built-In Oscillation-Based Self-Testing of a 2.4 GHz LNA in <tex>$0.35\mu \mathrm{m}$</tex> CMOS
Oscillation-based built-in self-testing (OBIST) is a promising technique for component testing in... more Oscillation-based built-in self-testing (OBIST) is a promising technique for component testing in RF systems-on-chip. We propose an OBIST scheme for a 2.4 GHz LNA in $0.35\boldsymbol{\mu} \mathbf{m}$ CMOS that integrates the switching and matching circuitry, thereby reducing chip area required for OBIST. We further demonstrate, in simulation, the use of differential frequency-selective on-chip power detection for both $\boldsymbol{f}_{\theta}$ and ${\boldsymbol{P}}_{\boldsymbol{out}}$ discrimination, negating the need for RF test equipment. It is found that the switched differential $\boldsymbol{f}_{0}$-based detection is a far stronger fault indicator, with detection probability above 60% in a majority of faults considered despite process variation.
A 13-nW Voltage Reference with Orthogonal Trimming of Absolute Value and Temperature Coefficient
An all-MOSFET voltage reference generator (VRG) with innovative trimming that orthogonally adjust... more An all-MOSFET voltage reference generator (VRG) with innovative trimming that orthogonally adjusts V<inf>REF</inf> and temperature coefficient (TC) has been designed in 0.18μm CMOS process. The circuit works from V<inf>DD</inf> = 0.5V, featuring V<inf>REF</inf>=239.9mV and TC =14.6ppm/°C. SPICE data reveal, for 0.5V ≤ VDD ≤ 1.5V, -40°C ≤ T ≤ 120°C and over all corners, post-trimming maximum spread of 1.63% and 34.5ppm/°C, respectively for ΔV<inf>REF</inf>/V<inf>REF</inf> and TC. Typically, consumption is only 13nW@120°C. Line regulation of 0.21%/V and rejection to supply-line noise of 115.5dB@100MHz are also predicted. Monte Carlo reveals post-trim 0.9% (3σ) accurate VREF.
Built-In Oscillation-Based Self-Testing of a 2.4 GHz LNA in 0.35µm CMOS
Oscillation-based built-in self-testing (OBIST) is a promising technique for component testing in... more Oscillation-based built-in self-testing (OBIST) is a promising technique for component testing in RF systems-on-chip. We propose an OBIST scheme for a 2.4 GHz LNA in $0.35\boldsymbol{\mu} \mathbf{m}$ CMOS that integrates the switching and matching circuitry, thereby reducing chip area required for OBIST. We further demonstrate, in simulation, the use of differential frequency-selective on-chip power detection for both $\boldsymbol{f}_{\theta}$ and ${\boldsymbol{P}}_{\boldsymbol{out}}$ discrimination, negating the need for RF test equipment. It is found that the switched differential $\boldsymbol{f}_{0}$-based detection is a far stronger fault indicator, with detection probability above 60% in a majority of faults considered despite process variation.
Design of an ULP-ULV RF-Powered CMOS Front-End for Low-Rate Autonomous Sensors
John Wiley & Sons, Inc. eBooks, Feb 4, 2020
Effect of Vth shifting in CMOS Transistors under radiation conditions when applying OBT: A case study
2023 IEEE 24th Latin American Test Symposium (LATS)
Contrôle de température à boucle fermée d'un capteur de gaz à semiconducteur
The Gallium Nitride semiconductor technology allows switching operation at high frequency and sup... more The Gallium Nitride semiconductor technology allows switching operation at high frequency and supports voltage levels compatible with medium power applications. Its emergence has resulted in a number of works investigating the feasibility of high frequency DC/DC converter prototypes primarily in terms of efficiency. The present paper goes one step beyond and reports electromagnetic emission measurements, both conducted and radiated, made on a DC/DC converter operated at 50 MHz Very High Frequency, 30 V input voltage and 7.5 W power level. The measured performances are tentatively assessed to drive the design of future VHF converters.
A 65-nm CMOS battery-less temperature sensor node for RF-powered wireless sensor networks
2016 IEEE Wireless Power Transfer Conference (WPTC), 2016
This work presents the design of a temperature sensor in a 65nm CMOS technology, which is powered... more This work presents the design of a temperature sensor in a 65nm CMOS technology, which is powered by harvesting the electromagnetic energy in the ISM frequency band (2.4GHz). The power consumption of the sensor was substantially reduced so that the energy required to operate could be stored in a 50μF external capacitor. The rectifier sensitivity has been improved so as to allow autonomous operation from a distance of 2m to a conventional Wi-Fi transmitter (2.4GHz@100mW). To achieving these features, all circuits were designed for operating at 0.5V supply voltage. The measured temperature value is transmitted within another frequency band, the European UHF (867 MHz), by using 4-FSK modulation.
A 90% Efficiency, 50MHz Buck Converter for Space Telecom Systems
Input switch configuration for sample and hold circuits in low-voltage operation
2014 Argentine Conference on Micro-Nanoelectronics, Technology and Applications (EAMTA), 2014
This work presents an implementation of Dessouky's bootstrapped switch optimized for 65-nm CM... more This work presents an implementation of Dessouky's bootstrapped switch optimized for 65-nm CMOS technology to attain a high linearity in front-end sample-and-hold (S/H) circuits [6]. The simulations of this design show that the spurious-free dynamic range (SFDR) achieves 100 dB for a single sinusoidal input signal of 36.36 MHz at fs=80 MHz.
GM-C design of a chaos machine generating the Lorenz attractor on a CMOS technology
Oscillation-based testing (OBT) and Oscillation-based built-in self-testing (OBIST) circuits enab... more Oscillation-based testing (OBT) and Oscillation-based built-in self-testing (OBIST) circuits enable detection of catastrophic faults in analogue and RF circuits, but both are sensitive to process, voltage and temperature (PVT) variation. This paper investigates 15 OBT and OBIST feature extraction strategies, and four approaches to threshold selection, by calculating figure-of-merit (FoM) across PVT variation. This is done using a 2.4 GHz LNA in 0.35 μm CMOS as DUT. Of the 15 feature extraction approaches, the OBT approaches are found more effective, with some benefit gained from switched-state detection. Of the four approaches to threshold selection (nominal-ranged static thresholds, extreme-range static thresholds, temperature dynamic thresholds, and simple noise-filtered tone detection), dynamic thresholds resulted in the highest average FoM of 0.919, with the best FoM of 0.952, with a corresponding probability of test escape P(T E ) and yield loss P(Y L ) of 5•10 -2 and 1.89•10 -2 respectively but requires accurate temperature measurement. Extreme static threshold selection resulted in a comparable average FoM of 0.912, but with less susceptibility to process variation and without the need for temperature measurement. Binary detection of a noise-filtered oscillating tone is found the least complex approach, with an average FoM of 0.891. INDEX TERMS Built-in self-test, circuit simulation, CMOS, design for testability, LNA, microwave integrated circuits, oscillation-based testing, PVT.
Oscillation-based testing (OBT) and Oscillation-based built-in self-testing (OBIST) circuits enab... more Oscillation-based testing (OBT) and Oscillation-based built-in self-testing (OBIST) circuits enable detection of catastrophic faults in analogue and RF circuits, but both are sensitive to process, voltage and temperature (PVT) variation. This paper investigates 15 OBT and OBIST feature extraction strategies, and four approaches to threshold selection, by calculating figure-of-merit (FoM) across PVT variation. This is done using a 2.4 GHz LNA in 0.35 μm CMOS as DUT. Of the 15 feature extraction approaches, the OBT approaches are found more effective, with some benefit gained from switched-state detection. Of the four approaches to threshold selection (nominal-ranged static thresholds, extreme-range static thresholds, temperature dynamic thresholds, and simple noise-filtered tone detection), dynamic thresholds resulted in the highest average FoM of 0.919, with the best FoM of 0.952, with a corresponding probability of test escape P(T E ) and yield loss P(Y L ) of 5•10 -2 and 1.89•10 -2 respectively but requires accurate temperature measurement. Extreme static threshold selection resulted in a comparable average FoM of 0.912, but with less susceptibility to process variation and without the need for temperature measurement. Binary detection of a noise-filtered oscillating tone is found the least complex approach, with an average FoM of 0.891. INDEX TERMS Built-in self-test, circuit simulation, CMOS, design for testability, LNA, microwave integrated circuits, oscillation-based testing, PVT.
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Papers by Carlos Dualibe