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  • Premo Group
  • Conchita Supervia, 13
  • 08028 Barcelona
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  • Patricia Mancera
  • +34 (951) 231320

PREMO presents the Third Generation Planar Transformers

(PresseBox) (Barcelona, ) In the last years the planar technology has became in the favourite of the designers of high frequency Switched mode power supplies. The use of high frequencies implies a reduction of passive components size obtaining better power densities in the above mentioned supplies.

Nevertheless, the high frequencies present a fundamental disadvantage: the losses increase for the proximity and skin effects, especially more than frequencies 100kHz. In difference to conventional power supplies, the planar transformers provide better qualifies: coiled coupling, the size, the repetitividad industrial and the profile. A typical planar transformer admits great simplicity spendthrifts what it is effective to the supplies costs.

From 1996, the Spanish PREMO has developed an ambitious planar technology program based on the increasing demand of the currents and high frequencies power supplies, and exhibiting a high efficiency. So every PREMO new planar has been more frivolous and more effective.

The principal planar transformers advantages on the conventional ones are the following:

- low profile structures: it has been verified that the low profile components have better efficiency volumétrica and a better power density for certain applications.
- Minor fugues inductance: Inserting coiled is very simple in the planar technology. This allows to minimize and to control for design, the fugues inductance of the coiled.
- Minor high frequency losses: The effect skin is minimized because that the thickness drivers diminishes.
- Better adjustment to the spendthrifts: an inductive planar geometry with a relation area/ more volume allows a better contact and spendthrifts assembly. The result is that it obtained minor thermal resistance.
- Better adjustment to its industrialization: The use of Printed Circuit Board (PCB) provides advantage as for the production process speed and automation.
- Better electrical and mechanical repeatitivility: This characteristic is very important especially when the final supply has a resonant topology.

The Third Generation design has centred in obtaining a more frivolous, more compact and more powerful product.

The planar transformers Third Generation has three families:

- AC/DC: It uses in AC/DC Switched mode power supplies. It includes a powers range between 15 and 5000 W.
- DC/DC: It uses in high power convertors DC/DC. It includes a powers range between 20 and 2000W.
- NS-DC/DC: it is designed to be compatible with the National Semiconductor IC's and the Texas Instrument family PWM UCC3580. It is ideal to use in convertors IBC (LM5033). It offers different adjustable power ranges to a variety of applications (LM5030). It is special for power suppies with currents raised for telecommunications (LM5041 and UCC3580).

Three new formats have been added: P015, P020 and P026.

PREMO designs its planar transformers across the unique simulation and finite elements analysis system. PREMO has an own high precision software from which it are obtained all the electrical critical parameters, among them, fugues inductance, parásita capacity, AC resistance and thermal performance. When the electrical design is validated, R&D PREMO department develops the component mechanics using tools CAD/CAM. PREMO has invested many resources in the Third Generation because if the design mechanical is optimized, electrical presentations and answers in electromagnetic compatibility tests are better.

PREMO's transformers surrender to reliability tests according to the international standards before its exit to the market. In addition PREMO possesses a unique test system that reproduces the worst functioning conditions. It is excited the primarily coiled with a square symmetrical wave with the specified work voltage, and secondary coiled it connects to changeable loads that it does that the transformer operates to the maximum possible power. In this moment it are realized all the thermal pertinent test in order to validate the results obtained in the simulation. The Third Generation compact structure does that these tests present even better results that the previous edition (2004).

Nevertheless, the most important new generation contribution it is its extraordinary adaptability for the putting in march in big quantities productions, about a million pieces / year for every code. PREMO offers two main mounting options, SMD or Pin Through Hole, and for high currents about 50Arms, direct connection. PREMO has developed a terminuses system (GWP) for SMD, specially thought to avoid component shades on the pad layout opposite to a reflow process in the production line of our clients.

From the first generation, the planar transformers are free lead products and fulfil with the European Union RoHS regulation. In addition the PREMO quality management system provides materials declaration sheets according to the European Union WEEE regulation. Our monitored and prohibited substances list is harmonized by the main electronic components world manufactures lists. In the previous months RoHS regulation entry into force in European Union, July 1, 2006, they have developed a lot of seminars and speech where the industry exposed the worries about the RoHS components reliability opposite to ageing and dampness tests. The PREMO Third Generation planar transformers has gone a step ahead and all its raw material has been selected to pass the above mentioned tests from the tin of the weld up to the insulating prepreg 1080 of the multigelds structures.

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