DC-DC converters have several advantages for developing electronic technology, but for mobile-based ground equipment, there are design challenges involved.
Thermal design is one of the key considerations for designers – especially when trying to optimize converter performance, or choosing the appropriate converter. Underestimating its complexity can lead to introducing serious obstacles to efficiency, so thorough attention to this issue is vital to make sure the optimal DC-DC converter is being used.
This blog post takes a closer look at the role played by thermal design in converters for mobile-based ground systems.
The impact of heat
Mobile applications can be a harsh and demanding environment for electronic devices, due to the heat that is generated, as well as ambient temperature conditions, can have a potentially disastrous impact on converters if it is not properly managed.
The generation of heat isn’t simply limited to poor functioning converters – even those that are highly efficient will still release thermal energy. It can also be difficult to quantify how much heat is dissipating, as the total power requirement is still often unknown at the preliminary stage.
The higher the operating temperature, then the greater the mean time between failures (MTBF) is likely to be, and this is especially important in mobile devices such as vehicular environments where a lot of heat is produced, but there is insufficient airflow to allow for cooling. So it’s essential for electronic designers to factor in thermal impact early on during the design process.
What to consider
To help designers to accommodate for the relevant level of cooling, a brick converter model can be used, to work with the relevant average thermal performance for a particular series.
One way to calculate the conversion factor required can be through use of a curve plotting output power against case temperature.
For example, if the maximum ambient temperature is known to the system designer, thermal impedance can be used to calculate the conversion factor to cool the environment to the appropriate level. Similarly, it is also possible to calculate heat-sink values needed to reduce the case temperature.
It is however, important to remember that as converters are components, they will need to be de-rated from both a temperature and power standpoint.
DC-DC converters can be extremely useful in regulating output voltage and improving efficiency. Their use can help to reduce the size of devices, allowing for more compact and streamlined design, as well as better battery management, and consequently the demand for low voltage devices with these converters is growing.
Their advantages have to be countered with a need to compromise effective design with a practical consideration of the associated thermal parameters. By reaching an appropriate balance between the benefits of DC-DC converters and the level of heat that is inevitably generated, engineers can reach optimum efficiency in their designs.
What are your thoughts on thermal considerations during the design process? Let us know what you think!