“Linear regulators have low noise and are advantageous for precise voltage supply, and buck converters are suitable for high-efficiency step-down methods. In this way, when designing a power circuit, developers must use components that are precisely suited to the design purpose to develop a cost-effective product that provides optimal performance for the purpose. ADI will continue to provide solutions that enable developers to efficiently design power circuits based on the latest technology.”

On the 22nd, Analog Devices held a 'Power Circuit Design Webinar with Analog Devices' through e4ds eeWebinar.

This webinar was led by ADI's Managing Director Noyil and was titled 'Understanding Power Components and Various Switching Regulator Topologies.'

Mr. Noil introduced the basic concepts and latest technologies of power circuit design, adding the latest trends in linear regulators and DC-DC converters.

■ Precision voltage supply linear regulator, power efficiency converter

Mr. Noil first explained the linear regulator, emphasizing that the greatest strength of this method is that the circuit configuration is simple and noise is very low.

Linear regulators are advantageous for providing stable power to precision analog circuits or sensitive electronic components because they maintain a constant output voltage while having little external interference or switching noise.

He also said that because the output voltage is managed very cleanly, it is suitable for high-precision circuits and is evaluated as reliable in applications sensitive to voltage fluctuations.

On the other hand, it was also mentioned that if the voltage drop between the input and output is large, unnecessary heat generation and energy waste may occur, which can be a disadvantage in terms of efficiency.

Along with this, Mr. Noil also explained in detail the characteristics of converters (especially switching regulators or DC-DC converters). Since converters perform voltage conversion using a switching method, energy loss is relatively small even when the difference between the input voltage and output voltage is large. It was revealed that it boasts high efficiency.

In particular, it can provide stable output even under various input voltage conditions, which is advantageous when the power supply environment fluctuates. However, it is explained that the internal circuit is complex and electromagnetic interference (EMI) or switching noise may occur due to rapid switching operation, so additional filtering or shielding may be required for direct use in sensitive analog circuits.

Mr. Noyle emphasized that the choice between these two power management methods ultimately depends on the requirements of the application.

He said that when a precise voltage supply is required and is sensitive to noise, it is better to choose a linear regulator, and when power efficiency is the most important application or when the input voltage fluctuates greatly, it is better to choose a converter.

■ Buck converter when voltage drops, boost converter when low voltage needs to be increased

Next, while explaining the power management converter, the characteristics of the two main switching methods, the buck converter and the boost converter, and the design considerations accordingly were emphasized.

Regarding the buck converter, Mr. Noyle explained that the buck converter is a 'step-down' switching power supply method that provides an output voltage that is lower than the input voltage.

This method has the advantage of being able to switch at high speeds to stably lower the output voltage while greatly improving energy efficiency.

However, he emphasized that appropriate filtering and PCB layout design are essential because electromagnetic interference (EMI) and switching noise that may occur due to such high-speed switching operations may be problematic.

Regarding the boost converter, it is called a 'strong' switching power supply method to obtain an output voltage higher than the input voltage.The converter is described as being highly efficient in that it can boost a low input voltage to provide the required high output voltage.

On the other hand, he added that boost converters also have noise and EMI problems that can occur during the switching process, as well as design difficulties due to increased output voltage, so additional circuit configurations or filtering technologies are needed to solve these problems.

Regarding the quantum choice, Noyle explained that the choice of the two converters depends on the application requirements.

He said that when a voltage step-down is required (i.e., high voltage → low voltage conversion), a buck converter is suitable, and conversely, when a low voltage needs to be increased (low voltage → high voltage conversion), a boost converter is more advantageous.

He also emphasized that while each method provides high efficiency, various factors such as noise management, EMI suppression, and circuit complexity that occur in the process must be considered together.

■ PCB, high-speed switching area and sensitive analog circuits must not interfere with each other

Finally, the importance and optimization of PCB layout was also discussed.

Mr. Noil emphasized that PCB layout design is not simply a matter of placing components, but a key element directly related to the performance and reliability of the entire system.

Looking at the key takeaways, EMI Reduction and Signal Integrity PCB layout plays a critical role in minimizing high-frequency noise and electromagnetic interference (EMI) that can occur in switching power supplies.

Noyle said the layout of signal lines and power/ground traces must be carefully optimized to ensure that high-speed switching areas and sensitive analog circuits within the circuit do not interfere with each other.

For example, the loop area of the circuit is minimizedHe emphasized the need for methods such as blocking noise by using a dedicated ground plane or by using a fire suppression system.

Thermal Management and Power Distribution Efficiency Both linear regulators and switching converters can have heat generation issues, and the PCB design layout is essential to effectively dissipate this heat.

In this regard, Managing Director Noh Il explained that it is necessary to prevent heat concentration by maintaining appropriate spacing between parts and designing heat paths, and to optimize the power distribution network to increase the efficiency of the entire system.

Within the PCB, small output filters, decoupling capacitors, inductors, and other components have a significant impact on power quality and stability.

Mr. Noyle said that the placement of these components must be carefully planned, and it is especially important to apply appropriate filtering and shielding structures around high-speed switching circuits to reduce negative factors such as parasitic inductance and capacitance.

Leveraging design tools and simulations Optimizing PCB layouts cannot be achieved by simply relying on experience or intuition.

Accordingly, he emphasized the need to predict potential issues from the early design stage by utilizing specialized CAD tools and electromagnetic simulation programs and to derive the optimal layout through an iterative verification process.

He said that because PCB layout is closely related to the entire system as well as individual circuits, it must be designed comprehensively considering interactions when used with other power management methods (e.g. linear regulators, buck/boost converters, etc.), and interference between data signals and power signals.

He also said that to increase the reliability and efficiency of the entire system, PCB design must be optimized beyond simple component placement to include the “invisible” elements of the system.

Lastly“ADI provides differentiated technical support to solve our customers’ design problems and will continue to introduce solutions for efficient power circuit design based on the latest technology,” said Mr. Roh Noyle, Managing Director.

Meanwhile, a rebroadcast of this webinar can be viewed at https://www.e4ds.com/webinar_detail.asp?idx=925 .