App note: Characteristics and applications of fast recovery epitaxial diodes (FRED)


All about ultrafast diodes app note from IXYS. Link here (PDF)

During the last 10 years, power supply topology has undergone a basic change. Power supplies of all kinds are now constructed so that heavy and bulky 50/60 Hz mains transformers are no longer necessary. These transformers represented the major part of volume and weight of a traditional power supply. Today they have been replaced with smaller and lighter transfomers, whose core materials now consist of sintered ferrites instead of iron laminations and which can operate up to 250 kHz. For the same power rating, high frequency operation significantly reduces the weight and volume of the transformer. This development has been significantly influenced by new, fast switching power transistors, such as MOSFETS or IGBTs, working at high blocking voltages (VCES > 600 V).

Apart from the characteristics of the transitor switches, the on-state and dynamic characteristics of the free wheeling diodes have a significant impact on the power loss, the efficiency and the degree of safety in operation of the whole equipment. They also play a decisive role when it comes to increasing the efficiency of a SMPS and to reduce the losses of an inverter, which clearly mandates that ultrafast diodes be used. The ultrafast diodes described here embrace all characteristics of modern epitaxial diodes, such as soft recovery, low reverse recovery current IRM with short reverse recovery times.

App note: Optimized diodes for switching applications


An app note from IXYS about choosing the right diode for efficiency and cost. Link here (PDF)

Great efforts have been made to improve power switches – MOSFETs and IGBTs – to decrease forward voltage drop and as well as to decrease turn-off energy. In switching inductive loads, the turn-on losses depend strongly of the behavior of the companion free-wheeling diode and now form the major part of over-all power losses. New developments like series connected diodes in a single package can greatly improve a given design. This paper shows how to choose the optimum diode using the specific example of a PFC circuit.

App note: Intelligent power switches for 48 V battery applications


Application note on controling Intelligent Power Switches (IPS) from STMicroelectronics. Link here (PDF)

For the last 15-20 years, the automotive electronics market has been moving from electromechanical relays to solid state components for driving all kind of loads.

It is obvious why: solid state components are smaller in size, lighter, silent, easy to mass produce because they are housed in SMD packages, and they boast an unrivaled number of switching activations. On top of this, the solutions based on silicon components have a much higher electrical efficiency and offer useful types of diagnostics such as short-circuit, overload and thermal protections, they can supply an actual image of the current flowing into the load, and so on. In fact, they are called “Intelligent Power Switches (IPS)” or “Smart Power MOSFETs” for good reasons. The key “switching” element is an N-MOSFET, with the relevant charge pump. Around the N-MOSFET, logic interfaces and other elements contribute to the protection of the MOS and they generate and manage diagnostic data.

App note: Position sensing technologies in automotive applications


An Autopad(TM) sensor from TT Electronics provides a new non contact position sensing. Link here (PDF)

Automotive design engineers are continuously seeking components that offer performance and flexibility beyond those of conventional position sensing technologies. Further still are the requirements that these devices be versatile and adaptable to a wide range of applications. This demand has led to the need for devices incorporating the best design elements from conventional contacting and non-contacting sensor technologies.

App note: Thermal management basics and its importance for LED luminaire performance and cost


Article about thermal management on LED luminaire from TT Electronics. Link here (PDF)

LED luminaires are being marketed today as an alternative lighting technology that reduces power consumption and maintenance costs for commercial and residential installations. Thermal management has a significant impact upon the lifetime, performance and cost of an LED luminaire. Without proper application of thermal management design principles, the potential benefits of solid state lighting and its ability to be successfully marketed will be reduced.

App note: Buried capacitive sensors for tamper protection


A short app note from Silicon Labs on burying pads to prevent snopping on keypads. Link here (PDF)

An individual’s financial matters are increasingly electronic in nature and decreasingly interpersonal. As financial institutions replace human interaction with electronic interfaces such as ATMs, the need to make electronic circuits tamper-proof becomes critical. A typical numeric keypad for financial transactions may contain up to hundred or more tamper prevention and detection features. Tamper detection circuits raise alarms and disable functionality, while tamper prevention features are designed to prevent intrusions and breaches. This application note addresses the elimination of copper pads on the accessible top surface of printed circuit boards (PCBs). Burying traces to internal layers of a PCB prohibits electrical contacts from snooping on copper elements within the PC board.

App note: Driving E ink segmented displays


Application note on driving E Ink displays from Renesas. Link here (PDF)

E Ink segmented displays are direct drive displays consisting of E Ink Vizplex Imaging Film sandwiched between two electrode layers, the top plane and the backplane, and then encased in an environmental barrier solution to protect the film and the segment electrodes. To get the most from E Ink segmented Displays, you need to be aware of proper design and implementation. Your reward will be sharp, precise images, a pleasant transition from one image to the next, and a long battery life.

App note: Grid-connected solar microinverter reference design


A good read from Microchip on the theory behind inverter design connected to grip power. Link here (PDF)

There are two main requirements for solar inverter systems: harvest available energy from the PV panel and inject a sinusoidal current into the grid in phase with the grid voltage. In order to harvest the energy out of the PV panel, a Maximum Power Point Tracking (MPPT) algorithm is required. This algorithm determines the maximum amount of power available from the PV module at any given time. Interfacing to the grid requires solar inverter systems to abide by certain standards given by utility companies. These standards, such as EN61000-3-2, IEEE1547 and the U.S. National Electrical Code (NEC) 690, deal with power quality, safety, grounding and detection of islanding conditions.

App note: On-grid solar microinverter on Freescale MC56F82xx/MC56F82xxx DSCs


Application note from Freescale Semiconductor about microinverter solution develop together with Future Electronics. Link here (PDF)

In recent years, demand for renewable energy has increased significantly. The development of devices utilizing clean energy such as solar, wind, geothermal, and fuel cells attracts more and more attention. Solar energy harvesting is developing fast and will play a more important role as a global energy source. One of the ways to capture solar energy is via photovoltaic power generation systems, which are connected to the grid through power inverters. Therefore, many companies are focusing on development of photovoltaic grid-tie inverters. Freescale offers digital signal controllers, the MC56F8xxx family, that are well suited to ongrid solar inverter designs.