Vicor Newsletter - Issue 3, Autumn 2005

Insight


Vicor Europe's Quarterly Newsletter
Issue 3, Autumn 2005
Vicor News

Vicor's flexible route to RoHS compliance

For many manufacturers product compliance to the European environmental RoHS hazardous material standard will be compulsory by 1 July 2006. To help ease our customers' transition to RoHS compliance, Vicor will be offering our standard Brick products in both RoHS compliant and non-RoHS compliant options. Customers who manufacture using lead/tin solder processes can continue to use our existing non-RoHS compliant products which incorporate lead/tin connector pins. Customers transitioning to RoHS can now select RoHS-compatible pin styles.

Evaluation samples of most RoHS compliant products can be ordered now and volume production will follow shortly.

Most of the Vicor product range will be available in a RoHS compliant form by January 2006. For further details of our RoHS strategy, including a product roadmap, please visit the RoHS area of our website.

Meet the people
Patrizio Vinciarelli - Chairman, President and CEO, Vicor Corp.
Quiz - Win a multimeter!
See if you can match the mixed up definitions and terms. Click here
New Product Information

High-boost harmonic attenuator module

Vicor's high-boost VI-HAM is a universal AC input, PFC front-end module that has been optimised for use with Vicor's V375 series of DC-DC converters. A single high-boost VI-HAM may be used with any combination of V375 series DC-DC converters up to 600 Watts, resulting in a power conversion system with high power density, few components, and low cost

High-boost harmonic attenuator module

Parallelable versions of the VI-HAM are available for applications requiring over 600 Watts of output power. In addition, the high-boost VI-HAM is fully compatible with Vicor's VI-26x and VI-J6x series DC-DC converters, giving designers the freedom to choose from the industry's broadest selection of DC-DC converters with outputs from 2 to 95Vdc, at 50 to 600 Watts.

The VI-HAM consists of a full-wave rectifier, a proprietary high-frequency zero-current switching (ZCS) boost converter, and includes active inrush current limiting, over temperature and short circuit protection, control, and housekeeping circuitry. For further information click here.

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Technical Tip

Output voltage trimming

The nominal output voltage of Vicor's DC-DC converter can be trimmed up or down within a specified range. Most of our 1st Gen converters can be adjusted between -50% and +10% (except outputs between 10V and 15V, which are limited to a range of +/- 10%). All our 2nd Gen converters can be trimmed down to 10% or up to 110% of nominal output voltage.

Fixed set output trimming can be achieved using a single resistor or by using a potentiometer when variable outputs are required. The use of an OpAmp or DAC gives you more flexibility to change the output voltage dynamically. Care has to be taken not to exceed the maximum voltage rating of the control pin provided in our datasheets. Usually a minimum pre load is necessary to reach the lowest output voltage. Please contact Vicor's applications engineering for more details.Do not exceed 0.25 Vdc drop between -S and -Out leads. This is an important consideration if OR'ing diodes are used - they should be located in the +Output lead to avoid exceeding this rating.

The trimming resistors, potentiometer, or active circuitry are connected to TRIM (1st Gen) or to SC (2nd Gen) respectively, and are referenced to the SENSE pins. Due to the lack of SENSE pins in our Micro modules, the trimming resistors are referenced to the -OUT and +OUT. To avoid noise being introduced into the module, the trim components should be located close to the module's pins.

For convenience, we provide trimming calculators for fixed and for variable output trimming on our web page. Please see both links below.

Click here for fixed output trimming calculators

fixed output trimming calculators

Click here for variable output trimming calculators

variable output trimming calculators
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Novel Applications - Medical Sector
MRI scanning system

MRI scanning system

The system is designed specifically for in-office musculoskeletal imaging, bringing MRI to the patient, and thus reducing the need for hospital visits.

MRI scanning system

The compact, modular design requires as little as 8.4m2 and the low field MRI magnet is optimized for orthopedic use and imaging of extremities. Patients remain outside the magnet at all times during the examinations, enabling constant patient-technologist contact. This MRI system uses Vicor's Junior modules in the temperature control system, where it is vitally important to keep the MRI magnets at a constant temperature.

3-D ultrasound systems

Some of you may remember the days when we could not make head nor tail of a pre-natal ultrasound. Those days are gone! Hi-tech ultrasounds now come in 3-D and are put on disks for parents to view at leisure in the comfort of their own homes and to share with family and friends. Originally Vicor's 1st Gen modules were used to power these ultrasound systems, but now the 2nd Gen modules have taken their place. The ultrasound equipment designers chose Vicor because of the low noise and interference levels of our products, the high density that our modules can provide, and the excellent technical support that we give.

3D ultrasound system