Differential temperature sensors: Review of applications in the test and characterization of circuits, usage and design methodology

Differential temperature sensors can be placed in integrated circuits to extract a signature ofthe power dissipated by the adjacent circuit blocks built in the same silicon die. This review paper firstdiscusses the singularity that differential temperature sensors provide with respect to other sensortopologies, with circuit monitoring being their main application. The paper focuses on the monitoringof radio-frequency analog circuits. The strategies to extract the power signature of the monitoredcircuit are reviewed, and a list of application examples in the domain of test and characterizationis provided. As a practical example, we elaborate the design methodology to conceive, step bystep, a differential temperature sensor to monitor the aging degradation in a class-A linear poweramplifier working in the 2.4 GHz Industrial Scientific Medical—ISM—band. It is discussed how,for this particular application, a sensor with a temperature resolution of 0.02 K and a high dynamicrange is required. A circuit solution for this objective is proposed, as well as recommendations for thedimensions and location of the devices that form the temperature sensor. The paper concludes with adescription of a simple procedure to monitor time variability.Postprint (published version

Thermal coupling in ICs: aplications to the test and characterization of analogue and RF circuits

In this presentation we cover how to use low frequency or DC temperature measurements to observe figures of merit of high frequency analogue circuits.Postprint (published version

Electro-thermal coupling analysis methodology for RF circuits

In this paper we present an electro-thermal coupling simulation technique for RF circuits. The proposed methodology takes advantage of well established tools for frequency translating circuits in order to significantly reduce the computational resources needed when frequencies of interest are separated by orders of magnitude.Postprint (published version

High-power test device for package thermal assessment and validation of thermal measuremetn tecniques

This paper describes the structure and thermal behavior of a high-power thermal test chip (up to 200 W/cm2) designed for power electronics package assessment, which has also been used for the validation of thermal measurement techniques. In particular, we show two application examples where the proposed device allowed the assessment of different power substrate technologies, and the validation of temperature measurement techniques used to characterize the high frequency behavior of circuits and devices in the frequency domain using the heterodyne technique.Postprint (published version

Frequency characterization of a 2.4 GHz CMOS LNA by Thermal Measurements

© 2006 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This paper presents a technique to obtain electrical characteristics of analog and RF circuits, based on measuring temperature at the silicon surface close to the circuit under test. Experimental results validate the feasibility of the technique. Simulated results show how this technique can be used to measure the bandwidth and central frequency of a 2.4 GHz low noise amplifier (LNA) designed in a 0.35 microns standard CMOS technology.Peer ReviewedPostprint (published version

Exercicis d’anàlisi de circuits, concebuts per a ser emprats en l’assignatura de Fonaments d’Electrònica

Conté exercicis resolts2011/201

Output Power and Gain Monitoring in RF CMOS Class A Power Amplifiers by Thermal Imaging

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.The viability of using off-chip single-shot imaging techniques for local thermal testing in integrated Radio Frequency (RF) power amplifiers (PA’s) is analyzed. With this approach, the frequency response of the output power and power gain of a Class A RF PA is measured, also deriving information about the intrinsic operation of its transistors. To carry out this case study, the PA is heterodynally driven, and its electrical behavior is down converted into a lower frequency thermal field acquirable with an InfraRed Lock-In Thermography (IR-LIT) system. After discussing the theory, the feasibility of the proposed approach is demonstrated and assessed with thermal sensors monolithically integrated in the PA. As crucial advantages to RF-testing, this local approach is noninvasive and demands less complex instrumentation than the mainstream commercially available solutions.Peer ReviewedPostprint (author's final draft

Single-MOSFET DC thermal sensor for RF-amplifier central frequency extraction

© 2017 Elsevier B.V. A DC thermal sensor based on a single metal-oxide-semiconductor field-effect transistor (MOSFET) is proposed to extract high-frequency electrical features of embedded circuits. The MOSFET sensor is monolithically integrated with the circuit under test (CUT) and then monitors by thermal means the DC power dissipated by the CUT, which carries high-frequency electrical information. After explaining the theory behind this testing approach, the paper demonstrates the feasibility of the proposed MOSFET sensor through simulations and experiments. These are carried out using a radio-frequency (RF) power amplifier as a CUT and thermally extracting its central frequency (440 MHz). The MOSFET sensor results are assessed using an infrared camera as a reference. The main advantage of the proposed sensing method is that the impact on the integrated circuit (IC) layout area is minimum, which is crucial when testing RF-ICs. Moreover, in comparison with previous works, the cost and complexity of the required instrumentation is lower.Postprint (author's final draft

MOSFET dynamic thermal sensor for IC testing applications

This paper analyses how a single metal-oxide-semiconductor field-effect transistor (MOSFET) can be employed as a thermal sensor to measure on-chip dynamic thermal signals caused by a power-dissipating circuit under test (CUT). The measurement is subjected to two low-pass filters (LPF). The first LPF depends on the thermal properties of the heat-conduction medium (i.e. silicon) and the CUT-sensor distance, whereas the second depends on the electrical properties of the sensing circuit such as the bias current and the dimensions of the MOSFET sensor. This is evaluated along the paper through theoretical models, simulations, and experimental data resulting from a chip fabricated in 0.35 mu m CMOS technology. Finally, the proposed thermal sensor and the knowledge extracted from this paper are applied to estimate the linearity of a radio-frequency (RF) amplifier. (C) 2016 Elsevier B.V. All rights reserved.Peer ReviewedPostprint (author's final draft