Vicor News New Product Information Technical Tip Novel Applications New on the Web

Vicor to be RoHS compliant this year

In February 2003 the EU introduced legislation restricting the use of certain hazardous materials in electrical and electronic equipment placed on the market after 1st July 2006. Called the RoHS directive the legislation restricts six environmentally hazardous materials including lead, mercury, cadmium and hexavalent chromium. Vicor is on track to be compliant with RoHS during 2005 and different product families will achieve compliance at different dates in 2005.

Vicor will be introducing RoHS compliant products that do not compromise form, fit or function, and performance and reliability will meet or exceed that of current products. Once a product family is compliant and has completed the necessary performance and qualification testing, reliability data will be available on request.

For more detailed information visit our RoHS section

28 V military COTS input filter

The M-FIAM5B: this recently introduced 28 V input
filter provides superior transient immunity to its
predecessors. Requiring minimal external components
when used with Vicor's 2nd Gen DC-DC converters the
M-FIAM5B meets MIL-STD-704E input requirements
as well as providing EMI filtering to MIL-STD-461E.

Other features include a 20 A output capability, inrush
current limiting and remote enable/disable. Measuring
only 56 x 58 x 13 mm The M-FIAM has proved popular
in ground mobile military systems.

Download a datasheet

Keeping one's cool

To provide a long service life, power supplies require adequate cooling. Heat is removed from the supply using conduction, convection and radiation cooling. The equipment casing is sometimes used to conduct heat away. Often additional cooling is required and ambient air (convection) or moving air, e.g. from a fan, is used to remove excess heat. What airflow is required and should an additional heatsink be used? These questions are answered by using Vicor's Thermal Design Calculator or graphically by using our published charts. The Technical Tip below explains how to use this data.

Technical Tip: Vicor's DC-DC converters are rated for operation at nominal output power at baseplate temperatures up to a maximum of 100 Degrees Celsius (85C for VI-200) without de-rating. One can easily determine the thermal design required to cool Vicor products by using the thermal charts in our Design Guides (2nd Generation) and Application Manuals (1st Generation). As Vicor DC-DC converter efficiency is almost independent of input voltage the maximum total power dissipation in the converter is determined primarily by knowing the output power required from the converter.

Vicor's system products are based on our DC-DC converters and their thermal performance is determined in the same manner as DC-DC converters by using the appropriate thermal charts.

For example: Verify that a 200 W, 28 Vdc output AC-DC FlatPAC does not exceed the maximum allowable chassis temperature at an ambient temperature of 55 degrees C.

                     For delivered output powers of up to 150 W reference to the datasheet shows that airflow of 100 LFM (200 LFM = 1 meter/sec) is required (see the red line in the chart below).

                     Increasing the airflow to 250 LFM will increase the available output power to 200 W while ensuring that the baseplate of the internal converter does not exceed its maximum temperature (see the green line in the chart below).

Knowing the baseplate temperature and the environmental conditions of the power supply Vicor's application engineering team can provide designers with the MTBF (Mean Time Between Failures) reliability data.

By optimizing thermal design early in the design process it is possible to significantly improve product reliability and hence increase product life times.

Further information on thermal considerations may be found in the thermal section of our website

1st generation modules go underground

Our 1st generation modules have found their way underground!

This highly sophisticated piece of inspection equipment crawls remotely around small and inaccessible spaces,inspecting ipelines, drains and sewers.

Vicor's product was an ideal solution for the crawler, not only being small and lightweight, but also providing a rugged and robust power supply, perfectly suited to the most challenging environments.

Additionally, we were able to condition the power and address the issues of voltage transients that are associated with running off a 600m cable.

PFC MicroS: winning combination of high density, low profile

One customer uses two different PFC MicroS configurations in a semiconductor test system. The system is a very large climatic chamber that is configurable to allow the test of different semiconductor families. Dependent upon the type of DUT (device under test) the configuration of the power system is adapted to the task. The power system has three 3-phase 10KW main transformers that independently power the climatic chamber compressor, the control system and the test system.

The test system uses 48 channels and each channel has its own dedicated test board that is capable of operating many DUTs. Each board in turn has up to seven Vicor converters powering the many voltages needed during test. It was the programmability of the output voltage of 2nd generation modules that enabled Vicor to provide a successful solution for this customer.

The PFC MicroS was used as an auxiliary power supply (48 pieces per test system) to generate either an additional 5/3.3 V auxiliary high current output for current intensive tests or a 24/48 V high voltage bus used primarily in testing automotive semiconductors.

Though the test system itself is large, the small form factor of the PFC MicroS was instrumental for this design win. The customer was able to offer an extended capability on its system mainly because the PFC MicroS could fit into the room left by the main power system. Any power supply with lower power density would not have fit!

Get a PFC MicroS datasheet.

If you have used Vicor modules in a novel application, we'd love to hear from you!

Product Configurator for your power supplies

Our online product configurator is a great tool for design engineers. Assisting you with the product selection process, the programme quickly leads you to the most suitable power supply solution for your application from the thousands of standard products Vicor offers. Depending on your input/output combination, you will be offered a choice of alternative solutions, together with information relating to compatible products and accessories. Try the product configurator.

Ask an Apps!

If you have any application questions, Ask an Apps. Use this section to submit your technical questions on any of our products, or related power supply design issues to our applications engineers. They are here to provide the product, application and technical support, assist customers need concerning our products and power solutions. They can evaluate specific customer design issues and offer a wide range of component-based power solutions that include distributed power, current sharing, N+1 redundancy, thermal management and compliance with safety and performance standards.

Just go to 'Ask an Apps' on www.vicor-asia.com/askaapps

In this circuit diagram, showing the connection of a FARM (Filter/Autoranging Rectifier) and a DC-DC Converter, there are five essential components missing, numbered 1 - 5. Put the right parts out of the box (A, B, C, D & E) below into their right place.