DC-DC converters are in growing demand across a variety of applications, and mobile-based equipment feature highly in the list of technologies taking advantage of them. But as their usage increases, it is also necessary to pay close attention to the design and application considerations that arise for DC-DC converters.
While they offer several advantages to designers and manufacturers, converters also have particular limitations, all of which need to be carefully and thoroughly addressed. Electrical emissions resulting from high voltage and current transitions can lead to parasitic capacitance coupling noise to the chassis, which can result in greater interference, while the generation of heat in components can also impact their functionality. These factors must be considered during the design stage, to prevent issues with components or devices.
This blog post takes a closer look at another important consideration for DC-DC converters – the impact of mounting.
Mounting and Vibration
When mobility is a necessary requirement for components, it can also expose converters to vibration, and the long-term effects of this can result in serious damage to them.
To manage the risk of damage, there are two aspects that need to be considered by designers – mounting components, and mounting the converter assembly.
One of the best ways to avoid the possibility of performance impairment is encapsulation, where the converter is potted in a thermally conductive material such as silicon based material. The potting material offers protection against shock and vibration, while it also acts as protection from moisture, and also disburses thermal energy away from components.
However, the size of the converter itself can affect the mounting process, as well as potentially increasing its susceptibility to vibration. Magnetics (transformers and inductors) tend to be the largest components, and reducing their size could reduce this risk. One of the ways this can be done is by using compact magnetics and power semiconductors, such as diodes, transistors and field-effect transistors, which have helped to create smaller packages. More portable power sources, which were once too large and difficult to build into devices, can also help reduce their size.
Assembling the DC-DC converter
An important point to remember when mounting a converter is to ensure that it is positioned and assembled correctly. Manufacturer guidelines for torque provide individual instructions for any threaded inserts, which may vary. As over-torquing can lead to damaging or deforming the mount surface, these should be adhered to carefully. In addition, by looking at the co-planarity and the finish of the mounting surface, it is possible to select the optimum thermal interface material.
While DC-DC converters are susceptible to some obstacles due to the issues faced by low source voltages, they remain an important and valuable aspect of component design. By allowing for greater efficiency and smaller sizing, they can help to develop components with better battery life and a less bulky physical design.
What are your experiences in DC-DC converters and the challenges faced with mounting? Let us know what your thoughts in the comments.