Understanding PCB Inductors: Definition, Calculation Methods and Step-by-Step Design Guide

Inductors are special components that help control sudden changes in electrical current. They work by storing energy in a magnetic field and then releasing it into the circuit, which helps reduce spikes or surges in the current. A type of inductor commonly used in electronic devices is the PCB inductor. In this article, we will explain what a PCB inductor is and show you a few ways to calculate its inductance value. By the end, you'll have a better understanding of how PCB inductors work and their importance in electronic circuits.

What is a PCB inductor?

A PCB inductor is a type of electronic component used in PCBs to store and control electrical energy. It is designed to generate and maintain a magnetic field when an electric current passes through it. The main purpose of a PCB inductor is to store energy in the form of a magnetic field and release it back into the circuit when needed. This property of inductors makes them essential in various electronic applications, including power supplies, signal filtering, impedance matching, and energy storage. PCB inductors come in different sizes and configurations, allowing for flexibility in design and integration into electronic circuits. They play a crucial role in ensuring the efficient operation and performance of electronic devices.

What is the purpose of an inductor?

Inductors have the function of generating electromotive force in the direction of reducing fluctuation when fluctuating current flows, and storing electric energy as magnetic energy. It has characteristics that allow direct current to flow easily while being highly resistant to high-frequency current flow.

Inductors have the following specific application purposes:

• Dividing necessary signals and unnecessary signals (filtering)

• Stabilizing voltage in a power circuit (smoothing)

• Matching impedance in a high frequency circuit

How do you calculate coil inductance?

Inductance is a term that every physics student should be familiar with. It has its own formula and is frequently combined with resistance and capacitance. Oliver Heaviside first coined the phrase in 1886. In addition, we use the L to represent inductors on circuit diagrams and inductance in equations, in honor of the eminent physicist Heinrich Let’s learn about the Inductance formula and how to use it to determine the inductance of any item.

The formula is as follows:

L = (μ₀ * μᵣ * N² * A) / l

Where:

• L is the inductance in henries (H).

• μ₀ is the permeability of free space, approximately 4π x 10^(-7) H/m.

• μᵣ is the relative permeability of the core material.

• N is the number of turns in the coil.

• A is the cross-sectional area of the coil in square meters (m²).

• l is the length of the coil in meters (m).

How to Design Inductors on a PCB?

To design inductors on a PCB, follow these steps:

1. Determine the required inductance: Identify the specific inductance value needed for your circuit design. This can be calculated based on the circuit requirements and desired performance.

2. Select the core material: Choose the appropriate core material based on factors such as the operating frequency range, desired saturation level, and size constraints. Common core materials include ferrite, powdered iron, and air.

3. Determine the core size and shape: Select the core size and shape that best suits your design requirements. Consider factors such as available board space, desired inductance, and magnetic field strength.

4. Calculate the number of turns: Determine the number of turns required to achieve the desired inductance value. This calculation depends on the core material, core size, and wire gauge being used.

5. Choose the wire gauge: Select the appropriate wire gauge based on the current rating and the available space on the PCB. Thicker wire gauges can handle higher currents but may require more space.

6. Determine the coil shape and layout: Decide on the coil shape (e.g., solenoid, toroidal) and layout that best fits your PCB design. Consider factors such as component placement, signal integrity, and electromagnetic interference.

7. Consider parasitic effects: Take into account any parasitic effects that may affect the performance of the inductor, such as self-capacitance and resistance. These effects can be minimized through proper design techniques and component selection.

8. Simulate and test: Use simulation software or prototype testing to verify the performance of the designed inductor. Adjust parameters as necessary to meet the desired specifications.

9. Document the design: Document the inductor design, including specifications, calculations, and any design considerations. This documentation will be useful for future reference and replication.

Designing inductors on a PCB requires a good understanding of electromagnetic principles, circuit design, and PCB layout techniques. It is recommended to consult with experienced PCB engineers or utilize specialized design software to ensure optimal performance. Video: https://share.vidyard.com/watch/eRWCX52WfspHX4UcREymYp?

Conclusion

PCB inductors are vital components in modern electronic circuits, responsible for managing magnetic energy and ensuring the smooth operation of various devices. You can contact us if you need assistance with any of the concepts.