Search Results for dc-to-dc converters

In this case study, the author describes the investigation of a defective DC-DC converter retrieved from an aircraft following the report of abnormal system behavior. Electrical testing, local probing, X-ray imaging, and cross-sectional analysis led to the discovery of cracks on several pins and in some of the solder material. The cracks were caused by different rates of thermal expansion and were remedied with the help of thermomechanical analysis, EBSD imaging, and phase map comparisons for thick and thin solder joints.

This article discusses the causes and effects of parasitic ringing in the gate drive circuit of dc-to-dc converters. It also presents experimental results validating a possible solution.

This article explores the failure of a DC/DC converter without start-up overshoot and provides solutions to a problem that is relevant to space electronic systems.

This columnn explores the idea that insights into the root cause of increasingly complex failures may be hidden in unanswered questions from past analyses, indicating that there might be more value in previous files than once thought.

This article discusses the primary differences between electrostatic discharge (ESD) and electrical overstress (EOS) and the circumstances under which they occur. It also explains how to differentiate ESD from EOS during failure analysis and how to avoid common misunderstandings and mistakes.

Scanning microwave impedance microscopy (sMIM) is an electrical measurement technique that can be used to determine dopant profiles in semiconductor devices. This article describes the basic setup and implementation of the method and demonstrates its use in the cross-sectional analysis of NMOS power transistors.

This article discusses the challenges involved in testing analog and mixed-signal ICs and provides practical guidance and insights on how to deal with them.

This article discusses the basic principles of dark current spectroscopy (DCS), a measurement technique that can detect and identify low levels of metal contaminants in CMOS image sensors. An example is given in which DCS is used to determine the concentration of tungsten and gold contaminants in an image sensor and estimate the dark current generated by a single atom of each metal.

There is a little known failure mechanism that affects dc coils, particularly those used in low-side-switched circuits. This mechanism involves electrolytic transport of copper from the winding in conjunction with chemical corrosion. For this phenomenon to occur, several conditions must exist simultaneously. This article discusses the conditions under which such failures occur and explains how to minimize their effects if not prevent them.

Scanning nonlinear dielectric microscopy (SNDM) is a scanning probe technique that measures changes in oscillation frequency between the probe tip and a voltage-biased sample. As the probe moves across the surface of a semiconductor device, the oscillation frequency changes in response to variations in dielectric properties, charge and carrier density, dopant concentration, interface states, or any number of other variables that affect local capacitance. Over the past few years, researchers at Tohoku University have made several improvements in dielectric microscopy, the latest of which is a digital version called time-resolved SNDM (tr-SNDM). Here they describe their new technique and present an application in which it is used to acquire CV, d C /d V-V , and DLTS data from SiO 2 /SiC interface samples.

This article provides a high level overview of high speed analog circuits and associated failure analysis techniques. It discusses the failure modes and mechanisms of voltage reference circuits, high speed op amps, and digital-to-analog and analog-to-digital converters, the fundamental building blocks used to create high speed analog devices. It also explains how to deal with difficulties involving circuit node access, circuit loading, and performance.

Scanning acoustic tomography (SAT) is widely used to detect defects such as voids and delamination in electronic devices. In this article, the authors explain how they improved the spatial resolution and detection sensitivity of SAT by switching from a conventional piezoelectric probe to a capacitive micromachined ultrasound transducer (CMUT) and by using pulse compression signal processing. They also present examples showing how the improvement makes it possible to detect very small defects in multilayer stacks and BGA packages whether in through-transmission or reflection imaging mode.

Scanning probe microscopy (SPM) refers to a suite of techniques that measure the interaction between a fine probe or tip and a sample in contact or close proximity. These interaction measurements allow the study of properties such as topology, magnetic and electric fields, capacitance, temperature, work function, and friction. The information obtained from SPM plays an important role in IC failure analysis.

This article explains how to find shorted components on PCB assemblies using infrared-based direct current injection, a nondestructive method that has several advantages over magnetic microscopy and voltage drop measurement techniques. An application example involving a power board failure is also provided.

The failure of a white LED backlight module in a portable computer illustrates the challenges that component and system suppliers must overcome in order to determine root-cause failure mechanisms and take corrective actions that address the problem.

A scanning electron microscope system measures voltage contrast on device-under-test surfaces. This article addresses a limited set of applications that rely on voltage contrast (VC) measurements in SEM systems, showing how VC measurements can probe electrical activity running at speeds as high as 2 GHz on modern active integrated circuits.

This article addresses the issue of capacitor failures, explaining how and why they occur and how to determine the cause. It describes the frequent but often overlooked reliability failure mechanisms of ceramic, foil, and electrolytic capacitors.

Using the example of smart card radio frequency identification (RFID) devices, this article examines electrostatic discharge risk scenarios encountered during assembly and in the field, and outlines basic countermeasures.

This article presents a complete business model for Failure Analysis (FA) as a high tech provider in the world of microelectronics. Part I introduces the fundamentals of such a model. It starts with the definitions of a business process, and then the analysis flows are presented. Finally, a Key Performance Indicator (KPI) based operation is developed. Part II of this article will appear in the next issue of EDFA, and it will address the implementation of such a model in an FA lab. It discusses the interdependencies of workload and cycle times—the pipeline management. This opens the path to quantitative target setting agreements with customers. A complete system builds a database that can calculate all the parameters for an FA lab tailored exactly to the demand of the customer. Such a database acts as a reference lab and represents best FA practice.

Automotive electronics are exposed to mechanical shock and vibration, thermal cycling, chemical attack, current and voltage spikes, electromagnetic interference, and other hazards. Early life failures, which are not uncommon, can be difficult to diagnose due to the many contributing factors. This article provides an overview of automotive electronic failures and presents guidelines for determining the root cause.