New-Tech Europe Magazine | Oct 2017 | Digital Edition

a soft-switching topology that is inherently low-noise, making it easier to develop high-performance systems. Size and Packaging Today electronic systems are often space constrained. Even if the goal is not to make the system as small as possible, such as products housed in standardized 19” rack units, reducing the size of the power system allows the space saved to be used to add additional functionality. Any calculation of size should also consider the peripheral components required by the regulator. With higher levels of integration and high switching frequency, the size and number of peripheral components can be reduced, which can potentially offer a greater space saving than simply picking a regulator in a smaller package. The package types available don’t only determine the space required: often smaller packages can be located closer to the load, enabling more accurate regulation at the load and faster transient response. In addition to size, weight can also be an important factor, particularly in applications where the equipment can move. Examples of such systems range from hand-carried portable equipment to automotive electronics and drones. Operating Temperature & Thermal Performance Regulators cannot be100%efficient, so they will always dissipate heat that must be removed. If a heatsink

is required, this can significantly increase both the size and weight of the power system. Failure to dissipate heat can also impact the system performance in other ways: for example, in lighting or display applications if the regulator causes an increase in temperature of the LEDs, this will reduce the intensity and change the wavelength, and therefore the hue, of the light generated. The regulator must function reliably across the range of temperatures to which it can be exposed. In general, more efficient regulators will be able to operate at higher temperatures, as they do not need to dissipate so much heat, but products from different suppliers can vary widely so it is important to check the data sheet. Additional Features In addition to the criteria described above, your application may require some specific functionality, which can limit choice. Examples of these additional features include: Paralleling Capability: if regulators can be paralleled, then higher output currents can be delivered. Not all regulators can have their outputs paralleled, as with many topologies this will cause instability. Constant Current Output: in battery applications, a constant voltage is needed to supply the load, but constant current is required for charging. Some regulators offer outputs that can be configured both as constant

current and constant voltage, making them ideal for these systems. Soft start: the ability to ramp up the voltage slowly helps to ensure the power system is stable, even when large amounts of capacitance are connected to the output of the regulator. Overvoltage protection: regulators that have protection to ensure they cannot deliver more than the defined output voltage ensure that the load will not be damaged even during a fault. Other protection circuitry might disable the regulator if the input voltage is out of range. Transient response: some loads rapidly change the current they demand. A fast transient response ensures that the regulator can deliver the power needed, without large output capacitors to store energy. Conclusion Although regulators are conceptually simple components – they take a voltage at the input and deliver a different voltage at the output – there are many factors that determine the best regulator for your application. Carefully considering the criteria outlined above will help to ensure you pick the ideal regulator for your system.

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