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16 Jun 2014

ap_WE_inductor_8_design_tips

A practical guide for the selection of power inductors for DC/DC converters from Würth Elektronik. [via]

App note: Power inductors 8-design tips - [Link]

14 Jun 2014

obr1543_1

To tell the truth, probably no, but we have for you a few hints for relays which are very close to an ideal.

Signal relay is almost an „ideal component“ thanks to a practically zero distortion and a total isolation of a switched signal from a control one. That is naturally one of the main features of all electromechanical relays, but at signal relays it´s especially valued, as we usually require switching of relatively small signals. Favorite and widely used are for example relays Fujitsu series B3 and B4 (miniature SMT and THT relays) and series AxW (miniature only 5mm high relay) – all with bifurcated gold-plated contacts for a high reliability.

A novelty in our portfolio is the series Fujitsu NA representing something like a “golden middle way “. With dimensions 7,4×14,9×9,7 mm it belongs to narrow miniature relay enabling a high density of components on a PCB. Even though relay NA is somewhat bigger than for example series B4, but it´s able to withstand higher AC current – up to 0.5A/125VAC (vs. 0.3A at series B4) and it also provides an extreme mechanical lifetime up to 100×106 , what´s approximately twice that of B4 series. Sensitive coils, with a consumption of 0.1-0.3W at majority of types enable a dense mounting without problems with overheating.

From the point of view of the lowest possible consumption are naturally the best latching relays (with a permanent magnet) controlled only by pulses. Usually they´re easy to recognize by a letter „L“ behind the series marking (for example NAL, JSL). In a Fujitsu signal relays overview and the Fujitsu catalogue can be easily found a comparison among particular types as well as detailed information about them. We try to keep the most favorite types always on stock, what´s also reflected in the substantial increasing of stock.

Does a universal signal relay exist? - [Link]

6 Jun 2014

F3Sizex600

by Steve Taranovich:

I recently spoke to Piyush Sevalia, Executive Vice President, Marketing at SiTime Corporation,about their newly introduced 32 kHz TCXO (temperature compensated oscillator) which they claim to be the smallest, lowest power device in the industry. With its tiny footprint and ultra-low power consumption, the SiT1552 MEMS TCXO decreases the size and increases battery life of wearable electronics and Internet of Things (IoT); such benefits are not achievable from legacy quartz devices.

SiTime enters wearables, IoT markets with 32 kHz MEMS TCXO - [Link]

6 Jun 2014

crystal2

IQD frequency products have introduced a new range of temperature compensated voltage controlled crystal oscillators (TCVCXO) in a miniature 8-pad 5 x 3.2 mm outline. The IQXT-210 series TCVCXO, offers frequency stability down to ±0.14ppm over the full industrial temperature range of -40 to 85ºC.

Powered from a 3.3V supply the IQXT-210 has a typical current draw of only 12 mA (dependent upon oscillator frequency). The frequency can be specified between 10 MHz to 50 MHz. Initially there are 11 standard frequencies available including 12.8 MHz, 19.2 MHz and 26.0 MHz. Output can be specified as either HCMOS, 15pF load or Clipped Sine, into 10k Ohms load.

Tiny TCVCXO gets close to oven–controlled crystal stability - [Link]


22 May 2014

Print

By Panasonic

Capacitors may seem simple enough, but specifying them has actually grown more complex in recent years. The reason why comes down to freedom of choice. The universe of capacitors has expanded greatly over the past few years, in large part because of capacitor designs that take advantage of advances in conductive polymers.

These advanced capacitors sometimes use conductive polymers to form the entire electrolyte; or the conductive polymers can be used in conjunction with a liquid electrolyte in a design known as a hybrid capacitor. Either way, these polymer-based capacitors offer a performance edge over conventional electrolytic and ceramic capacitors. [...]

The various polymer and hybrid capacitors have distinct sweet spots in terms of their ideal voltages, frequency characteristics, environmental conditions, and other application requirements. In this article, we will show you how to identify the best uses for each type of advanced capacitor. We will also highlight specific applications in which a polymer or hybrid capacitor will outperform traditional electrolytic or ceramic capacitors.

Understanding Polymer and Hybrid Capacitors - [Link]

15 Mar 2014

obr1490_1

If you have in your “drawer” a universal 1000V diode in a miniature SOD123FL package, you have a solution for many circuits. 

Small/ bigger, with a lower- or rather with a higher cut-off voltage, solderable by wave or by reflow … these are for example some of the criteria when selecting a universal rectifying diode. However if you already know, that 1A current and a middle speed are sufficient for you, then we can say, that only one type will be sufficient for you in majority of cases – SL1M from company Diotec.

Standard silicon diodes show only a minimal dependency of VF from a cut-off voltage – in opposite to Schottky diodes, where a choice according a cut-off voltage is important in order to reach low losses (as a forward voltage – VF is noticeably higher at types with a higher cut-off voltage).

In other words, if a Schottky diode transfers for example 1A current, there´s a significant difference in a VF between types with a lower cut-off voltage in comparison to types with a higher cut-off voltage. However common silicon diodes don´t have this dependency, thus in general it dosen´t matter, whether we´ll use a „100V“ diode or a „1000V“ diode on a given place (if we don´t use a possible breakdown intentionally). So if can choose between a 400V and 1000V type for a similar price, nothing prevents us to better buy a 1000V type and to have a surety of universal usage – for example even for a direct rectification of a mains voltage. As a result we´ll gain for example a higher resistance to various overvoltages.

SL1M offers such versatility thanks to a very good price and also thanks to its dimensions, because it belongs to the smallest 1A diodes in the market. The only requirement if we want to use a maximum current of 1A is, that it´s necessary to observe a minimal pad dimensions (copper area) of approx. 5x5mm at both sides. This won´t be a problem for the most of applications, as to this area also contribute surrounding solder pads of other components (if they don´t generate heat). Naturally, in this case we mustn´t use at the PCB design a thermal isolation of pads (so called thermals), but only a non-solderable layer (solder resist).

Detailed description contains the Diotec SL1 datasheet and many useful documents can be found in our recent article “Do you need diodes? – Diotec has them“.

SL1M – when one diode can replace several types - [Link]

28 Jan 2014

obr1469_1

If you don´t have enough space on a PCB, maybe you´ll benefit from dual connectors for SIM cards and memory cards.

Usually there are more than enough reasons why to save space. Especially at handheld devices it´s almost always desirable that they were miniature and lightweight. We bring you two useful SMT connectors able to solve a problem with insufficient PCB space:

  • microSD+SIM card socket – 112G-TA00-R, 2×8 pinov, push-push for uSD/ push-pull for SIM, SIM/SD cards are mutually rotated in 90°
  • 2x SIM card socket – 115H-BA00, push-pull

Both sockets are made of a stainless steel and the plastic part is from an LCP (liquid crystal polymer) class UL94-V0 (self-extinguishing). Compact construction of both connectors is also reflected in a low profile of 2.7/ 3 mm.

“Doubledecker” can be found not only in London - [Link]

5 Jan 2014

obr1463_1

Xeno Lithium batteries offer high capacity at extremely low self-discharge and are able to supply your device for many years.

Primary Lithium batteries (Lithium thionyl-chloride, LiSOCl2) represent batteries with the highest energy density (Wh/kg), moreover able to operate without problems even in strong frosts. Perhaps their only technical “drawback” is the fact, that they´re only suitable for appliances with low current demands (up to tens of mA). However this “drawback” is already considerably overcome, because with modern components it´s easily possible to design devices with miliWatts power consumption. In principle are the Lithium primary (non-rechargeable) batteries suitable for backup (for example memories) and for power supplying devices with low power consumption, where it´s possible to reach even more than 10 years lifetime. This is naturally a huge benefit, as it enables to construct a device fully independent from external power supply, or without necessity of an external power supply and similar. At the same time it will also eliminate necessity to use an adapter or further electric installation.

These Lithium batteries operate on a principle of reaction Li+SOCl2. Arrising LiCl film on an anode has insulating properties. It provides excellent storage properties and energy preservation, because this passivation layer blocks auto reaction of Li+SOCl2 (self-discharging). Properties of Lithium batteries are also affected by the way and the length of stocking, and it´s possible, that after loading a battery, a short-time voltage drop will occur because of this passivation layer. Maximum capacity usage can be reached at a certain range of discharge currents (according to a diagram at every battery type). If a Lithium battery is intended to supply circuits with a short-time pulse demands, it´s very suitable to use a large capacitor or a supercapacitor connected in parallel with a battery. A capacitor in these cases will supply a bigger energy amount for a fraction of time and from the battery point of view a circuit then appears as one with significantly lower power consumption peaks. This contributes significantly to a maximum capacity usage and it´s also beneficial for a device itself thanks to minimum voltage drop at pulse power consumption.

Nominal voltage of LiSOCl2 batteries is 3,6V and a big advantage is a wide operating temperature range -55 to +85°C (max 150°C). Company Xeno Energy is a producer specializing in Lithium batteries and as one of few in the world they an ISO13485 certification for usage of batteries in medical devices. Further information will provide you the Xeno short form catalogue as well as detailed datasheets of Xeno batteries. In the Xeno production portfolio can also be found special batteries with a higher pulse capacity and type for extra high temperatures -55 to +130°C.

10 years of operation on 1 battery? - [Link]

21 Dec 2013

International Rectifier’s IR3846 is a member of the Gen3 SupIRBuck family of highly integrated synchronous voltage regulators. IR3846 is a compact DC-DC regulator with a single input supply without the need of an external VCC with its internal LDO and has a high current output of up to 35 A. Being part of the Gen3 SupIRBuck family, it has a corrective and unique modulation feature that gives a jitter-free and noise-free operation allowing higher frequency and higher bandwidth operation for better transient response. The device is very efficient and ideal for power applications of enterprises requiring space such as netcom server/storage, distributed point-of-load power architecture, and embedded telecom systems that involve high power density.

With a market price of $29, IRDC3846 evaluation board is highly efficient and cost-effective having multiple features. The PCB is a 200 mm^2, 6-layer board mounted with few passive components. Some of the important features of the board include: digital soft-start up, power good operation, overvoltage protection, thermal shutdown, and programmable switching frequency, which is flexible for different applications ranging from 300 kHz-1.5 Mhz. It is designed to a well-regulated input supply of +12V and configured for remote differential sensing.

The IRDC3846 evaluation board is very easy-to-use. Simply connect a +12V input supply at VIN+ and VIN- and a maximum of 35 A load should be connected to VOUT+ and VOUT-. If external VCC is required in an operation, Vin and VCC pins should be shorted together by installing a 0 ohm resistor. Other than remote sensing, the board can also be configured for local sensing by changing the resistors needed for operation. The length of the on-board power ground is minimized for better efficiency. Using separate power ground and analog ground, both can be connected together using a 0 Ohm resistor.

If you need a low voltage, high current regulator, IR3846 definitely should be considered. Having a small footprint, the device has exceptional capability offering high density. It is likely suitable for many applications in network communication and storage systems.

International Rectifier SupIRBuckTM IRDC3846 Evaluation - [Link]

4 Dec 2013

LT8614

The LT8614 is a 4A, 42V input capable synchronous step-down switching regulator. A unique Silent Switcher architecture reduces EMI/EMC emissions by more than 20dB, well below the CISPR 25 Class 5 limit. Even with switching frequencies in excess of 2MHz, synchronous rectification delivers efficiency as high as 96% while Burst Mode operation keeps quiescent current under 2.5μA in no-load standby conditions. Its 3.4V to 42V input voltage range makes it ideal for automotive and industrial applications.

LT8614 – 42V, 4A Synchronous Step-Down Silent Switcher with 2.5μA Quiescent Current - [Link]



 
 
 

 

 

 

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