An Introduction to Voltage Regulators
A voltage regulator is a device that provides two functions: changing the input voltage to a different level at the output and regulation, or maintenance of a constant output voltage despite changing load conditions. They are an important component in any power system, and choosing the right regulator for your system is crucial in developing an optimum solution. In this blog, we will discuss the types of regulators and how to decide which one is best for you.
There are three basic categories of regulators: buck, boost, and buck-boost. Buck regulators are regulators with an output that is lower voltage than the input, boost regulators are regulators with an output that is higher voltage than the input, and buck-boost regulators are regulators that can supply output voltages that are higher, lower, or identical to the input. In most applications, voltages are stepped down from the bus to the load, meaning buck regulators are the most commonly used. Other applications, such as when DC power must be transmitted using a long cable, the losses resulting from the power traveling a great distance can be reduced through the use of a boost regulator.
When selecting a regulator, the most important criteria are its input & output ranges, efficiency, noise, and operating temperature/thermal performance. Though applications commonly specify a certain voltage, others require an adjustable output. This can be for a number of reasons, but is most likely because the loads will change and the voltage needs to be able to compensate for this. Another benefit of using regulators with wide input and output ranges is that a single regulator can be used in many different situations, reducing inventory costs.
Another important factor to consider the regulator’s efficiency. Using a regulator with high power losses will make it nearly impossible to meet efficiency goals. It is also important to note that regulatory efficiency is not constant, and the device’s efficiency will generally fall dramatically as the step-down/step-up ratio increases and the current drawn from the output decreases. Most modern regulators offer high efficiency as well as consistency across their entire operating range.
Noise is yet another criteria to note when selecting a regulator. In systems with sensitive analog components, the power supply noise can limit overall performance and make it more difficult for a device to be EMC (electromagnetic compatibility) certified. The regulator’s topology is key to achieving low noise - it is easier to use a component that doesn’t generate noise than it is to try to filter that noise out.
The final consideration to make when choosing a regulator is its operating temperature and thermal performance. Regulators cannot have perfect efficiency, so there will always be heat that must be removed. A heatsink can be used, but this can increase the size and weight of the power system, affecting efficiency. However, failure to dissipate the heat can be detrimental to the system in other ways. For example, in lighting or display applications, if the regulator causes the temperature of the LEDs to increase, they will reduce in intensity and alter the light generated. A regulator must function reliably across a range of temperatures. Generally speaking, more efficient regulators can operate at higher temperatures, because there is less heat for them to dissipate. That said, different regulators from different manufacturers can vary greatly, so the product manual should always be consulted.
At NSN Sourcing, owned and operated by ASAP Semiconductor, we can help you find all types of regulators in addition to many other parts for the aerospace, civil aviation, defense, electronics, and IT hardware industries. Dedicated account managers are always available and ready to help you find all the parts and equipment you need, 24/7-365. For a quick and competitive quote, email us at sales@nsn-sourcing.com or call us at 1-720-923-2840.
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