Patel A.,Vicor Corporation
Conference Proceedings - IEEE Applied Power Electronics Conference and Exposition - APEC | Year: 2015
Most of the available DC - DC converter solutions are buck converters. There are very few boost converters with the performance expected of their buck counterparts. The SAC (Sine Amplitude Converter)  -  provides an elegant method of resolving the challenges of designing DC - DC converters to provide isolated, regulated and step-up voltage transformation. A real world implementation of a 50 V to 200 V step-up DC - DC converter is described. Significant data are presented to characterize the efficiency and power density of this solution compared to conventional approaches. This technique provides a +6% increase in efficiency, more than 4 times increase in power density and high gain factors. © 2015 IEEE.
Sullivan J.,Vicor Corporation
Power Electronics Technology | Year: 2011
Electricity is generated somewhere and it's distributed to the user (to the data center, say) where it is further distributed, usually in a number of steps. Somewhere along the line, it is changed from AC to DC for final consumption by arrays of processors at increasingly smaller voltages and higher currents. Efficiency drops at every conversion, so it is desirable to keep the number of conversions low. The new VI BRICK BCM Arrays are ideally suited for server applications using a PFC front end that require relatively high power levels with challenging thermal issues. The offline power can be bussed to the motherboard and converted to either 48V or 12V, which minimizes distribution losses, reduces conversion steps, improves efficiency, and reduces overall cost. These products can be used in a wide variety of applications that require high efficiency, high power density, improved thermal management, low noise, fast transient response, and overall design flexibility.
Schultz C.P.,Vicor Corporation
IEEE Aerospace Conference Proceedings | Year: 2013
The original Coupled Leakage Model of a multiple winding transformer embodies the subject magnetic circuit by magnetically coupling the secondary referenced leakage inductances. Leakage inductance is included in each of the multiple secondary windings, however this model introduced an effective coupling coefficient between the leakages. The model is further extended here to show that it fully supports alternate forms whereby the leakage inductance can be reflected in part, or in total, into the primary winding. Experimental and circuit simulation results are included to verify these alternate forms of the model. Lastly, a two winding version of the Coupled Leakage Model is compared to an existing two winding model in order to illustrate other differences. © 2013 IEEE.
Whittier R.,Vicor Corporation
SMT Surface Mount Technology Magazine | Year: 2014
Previous experimentation on a highly miniaturized and densely populated SMT assembly revealed the optimum stencil alloy and flux-repellent coating for its stencil printing process. Production implementation of the materials that were identified in the study resulted in approximately 5% print yield improvement across all assemblies throughout the operation, validating the results of the initial tests. A new set of studies was launched to focus on the materials themselves, with the purpose of optimizing their performance on the assembly line. Using a similar test vehicle as the prior experiments, DOEs characterized key aspects of the stencil manufacturing process by varying the laser cutting parameters and coating materials. As the scope of the DOE grew, it also included evaluation of new materials and a comparison of microBGA aperture designs. Eventually, additional runs were added to investigate the effects of nanocoating on wipe frequency and compare two different stencil cutting processes. Results of the prior tests are reviewed, and the new test vehicle, experimental setup and results are presented and discussed.
Patel A.,Vicor Corporation
Conference Proceedings - IEEE Applied Power Electronics Conference and Exposition - APEC | Year: 2016
This paper describes a new zero voltage switching (ZVS) bidirectional DC-DC converter (BDC) module. Compared to existing bidirectional DC-DC converter (BDC) modules for the same application, the new BDC module has the advantage of high efficiency, high power density and isolation. These advantages make the new BDC promising for medium and high power fuel cell, solar cell and battery applications where high power density, high efficiency, high reliability and lightweight power converters are needed. A real world implementation of 384 V to 48 V and 48 V to 384 V BDC is described, implemented and simulated using existing old components and proposed new power components for power level up to 1.65 kW. A new BDC provides a +13.5% increase in efficiency at 10% load, a +3.4% increase at 50% load and a +1.5% increase at 100% load in both forward and backward mode and more than double power density. © 2016 IEEE.