Electronics-Lab.com Blog

Tutorial: Creating Accurate Footprints in Eagle @ The Adafruit Learning System…

While sometimes quick and dirty works fine for footprints, if you ever have to deal with enclosures or particularly dense boards, you’ll soon find out that accurate footprints can make your life much easier.

There are some really nice, detailed and accurate footprints in the default Eagle libraries, but there aren’t a lot of resources out there on how to create them.  This guide will hopefully serve that purpose, highlighting what works for me making connectors and similar types of footprints.

Creating Accurate Footprints in Eagle - [Link]

General Discrete Package Poster – [PDF]
Discrete Flat No-Leads (DFN) ICs -  [PDF]

The LTM4620 is a dual 13A per output (or single 26A output) DC/DC μModule step-down regulator that delivers up to 100A when four devices are current shared. The LTM4620 is a complete DC/DC regulator system in a 15mm x 15mm x 4.41mm LGA package, including inductors, power stages and all control circuits. For optimum heat dissipation, an integrated top side heat sink removes heat quickly and evenly.

LTM4620 – Dual 13A or Single 26A DC/DC µModule Regulator with integrated heatsink  - [Link]

Thanks to their very low equivalent serial resistance (ESR), they provide a very worth function in power supply parts of various devices. In many cases, there´s no need to add any other types of filtering capacitors anymore. 

SMD ceramic capacitors are nowadays commonly available in relatively very high capacities of units to tens of uF, while keeping small dimensions (0603 – 1210). There are also available higher capacities in bigger packages, but the offer of producers is especially reach at these small packages (0603-1210) and prices are significantly better in comparison to a recent past.

Why to use a ceramic capacitor? First, it has a substantially lower value of ESR than electrolytic capacitors and also lower than tantalum ones. This is reflected in low losses and outstanding filtering properties even at high frequencies and high currents, what is especially beneficial at power supply of fast semiconductors and in switch-mode power supplies. Low power consumption of modern components enables to decrease an overall capacity of capacitors in a power supply part, that´s why in many cases a few uFarads are sufficient. A big advantage is a long lifetime too, because they don´t contain any liquid electrolyte. Naturally, in devices, where high current peaks occur, it would be economically inefficient to use ceramic capacitors only. In such cases a combination of ceramic and tantalum or electrolytic capacitors is ideal.

In our offer can be found more types, also a novelty in our offer – 2,2uF/10V/0805 from the X7R mass from company YAGEO (please note a significantly lower price at purchase of 50 pcs and more). The X7R mass ensures very good properties in a wide range of temperatures and voltages. Detailed information will provide you the X7R, X5R and Y5V documents. In case of interest about any YAGEO component, please contact us at info@soselectronic.com

Do you utilize ceramic capacitors for power supply filtering? - [Link]

madworm writes:

This is a simple constant current sink. It can be used to simulate a DC load. Need for it had arisen as I acquired a couple of cheap DC-DC converters and needed a way to test them, to see if they really put out the amount of current as advertised.

Some of the specs: 20V, 5A, 20W continuous dissipation, reverse polarity protection, 4mm banana-type binding posts for easy multimeter and load connection, current calibration with a 25-turn trimmer, 10-turn wire-wound potentiometer to set the current.

Simple DC Dummy Load - [Link]

element14 has teamed up with top suppliers, including Texas Instruments, Wurth Elektroniks and Cadsoft, to launch a new wireless power microsite. Designed to accelerate the integration of wireless power solutions in popular applications, such as smart phones, digital cameras and more, the site gives engineers access to a wide range of technical experts, complimentary webinars, product roadtests, and safety and compliance standards.

Engineers are invited to learn more by registering for a free webinar – “Charging Innovation – Cut the Cord” – on Thursday, Sept. 20 at 3 p.m. GMT/9 a.m. CDT. Attendees will see a demo of the new microsite, an overview of wireless power reference designs, and an opportunity to have questions answered during a live Q&A session following the webinar.

Wireless power integration made easy with TI’s bqTESLA evaluation modules - [Link]

We introduce to you a modern communication converter intended for connection of industrial M-Bus devices to the Ethernet, using the LAN/serial interface module XPort.

Usage

The communication converter is used in industry and building automation for data acquisition from heat consumption meters, flow meters, power consumption meters etc. It supports a connection of 1 to 5 M-Bus slave devices and a bus with devices connected can reach up to a few hundreds of meters length, depending on a connection quality, communication speed and additional protections. Connection of the interface module with a PC application can be realized by a virtual COM port, or directly through a TCP/IP connection. Connection through a virtual serial port is suitable for older programs, suitable only for a serial communication interface. Configuration of the interface module is possible via a password protected web interface.

Main Features

A construction of the interface module is based on practical experience from implementing of communication interfaces in an industrial environment. In order to reach a high reliability and immunity, the module has an above-standard protection against overvoltage. M-Bus port is resistant to a continuous shortcut, overload and it contains a filter increasing the resistance of communication to disturbances. M-Bus port is galvanic isolated from power supply, as well as from an Ethernet interface, to ensure a high overvoltage immunity and it prevents ground loops creation. A range of a DC and AC power supply has a wide range and the power supply port has an overvoltage protection, as well as a self-resettable PTC current fuse.. The module is in a robust aluminium enclosure, with a possibility of mounting to a 35mm DIN rail. For a simple assembly and replacement is the connection of leads realized by plug-in connectors. Operation statuses are indicated by six LEDs for a quick detection of an actual module status, its work and an indication of possible communication errors. The „overload/short“ LED diode differs two basic M-bus link error statuses. A shortcut is indicated by a continuous light and an overload by blinking.

Customer solution: M-Bus to Ethernet communication converter – EthMBus-5 - [Link]

Brian Chu writes:

Batteries often serve as the main energy source for portable electronic devices. Although they depend on batteries, portable consumer electronic products, such as GPS devices and multi-media players, often consume energy directly from an ac-dc wall adapter or accessory power adapter (or “Auto Adapter”) when the battery is low or the device is in a stationary mode. Due to their cost effectiveness over their useful life, rechargeable batteries are often used for the power source of the portable electronic device. Attributes such as “relatively high energy density” and “maintenance free” make Lithium-Ion (Li-Ion) batteries popular in the portable consumer electronic products. Refer to the application note, AN1088, “Selecting the Right Battery System For cost Sensitive Portable Applications While maintaining Excellent Quality” (DS01088) for characteristics of Li-Ion batteries. Some examples of how to properly design with Li-Ion batteries will be discussed in this application note.

Designing A Li-Ion Battery Charger and Load Sharing - [Link]

The essence of a proper and long-term operation of every device, is to use reliable components. From this point of view, relays Fujitsu are a synonym of reliability and a long lifetime.

To use a classic electromagnetic relay or rather an SSR – that´s the question, which apparently can´t be answered expressly, but pros and cons of both technologies are well known and information are easily available. We described to you features of solid-state relays for example in the article „Semiconductor better than a conductor?“. On the other hand, classic electromagnetic relays are still perspective, their features are continuously being improved and modern relays surprise by relatively small dimensions. To advantages of electromagnetic relays belong a high resistance to various power peaks, overvoltages and other disturbances. Price is also the factor saying in favor of electromagnetic relays.

Fujitsu FTR-K1 relays are power relays with a low profile, reflecting long-term experience of company Fujitsu. FTR-K1 replaced the over 20 years used VSB series relay, with which it is pin-compatible. High switching (16A) and inrush (80A) current, isolation strength up to 10kV, coil wound with a class F wire (155°C), cadmium-free contacts and RTII sealing make FTR-K1 literally a universal relay. FTR-K1 series is available in various versions – for example with up to 120A inrush current (K1-KS), with a transparent cover (K1-RG) and also with tab terminals for a simple load connection in the application (K1T).

As a standard stock in our offer can be found types FTR-K1CK005W, FTR-K1CK012W and FTR-K1CK024W with 5, 12 and 24V coils and one change-over contact (1CO, SPDT). We´re also able to supply other versions upon a request. Detailed information will provide you the Fujitsu FTR-K1 datasheet.

Personified reliability – Fujitsu FTR-K1 relay - [Link]

Researchers at TU Vienna have developed a special ‘photografting’ technique that allows molecules to be positioned in a 3D substrate to produce more versatile and accurate sensors for ‘lab on a chip’ devices. The researchers had previously explored new kinds of 3D printers, but 3D printing is not suitable for the envisaged applications because putting together materials from tiny components with different chemical properties is very complicated. Instead, they took the approach of starting with a three dimensional scaffold and attaching the desired molecules at exactly the right positions.

The process begins with a hydrogel with large pores through which molecules or even cells can migrate. Specifically selected molecules are introduced into the hydrogel mesh, and then certain points are blasted with a laser beam. This causes photochemical bonds to be broken where the focused laser beam is most intense, creating highly reactive intermediates that bond to the hydrogel in their vicinity very quickly. The precision depends on the laser’s lens system; the researchers were able to obtain a resolution of 4 µm.

Various molecules can be used, depending on the application. 3D photografting is useful not only for bio-engineering, but also for other fields, such as photovoltaics or sensor technology. It allows precise positioning, in very small spaces, of molecules that bond to specific chemical substances and allow them to be detected in a ‘lab on a chip’. [via]

Photografting: 3D Printing with Molecules - [Link]