{"id":2967,"date":"2026-06-19T17:13:29","date_gmt":"2026-06-19T09:13:29","guid":{"rendered":"http:\/\/www.oryggisblod.com\/blog\/?p=2967"},"modified":"2026-06-19T17:13:29","modified_gmt":"2026-06-19T09:13:29","slug":"how-to-design-an-integrated-transformer-for-a-specific-self-resonance-frequency-483d-919a52","status":"publish","type":"post","link":"http:\/\/www.oryggisblod.com\/blog\/2026\/06\/19\/how-to-design-an-integrated-transformer-for-a-specific-self-resonance-frequency-483d-919a52\/","title":{"rendered":"How to design an Integrated Transformer for a specific self – resonance frequency?"},"content":{"rendered":"

Designing an integrated transformer for a specific self – resonance frequency is a complex yet rewarding task. As a seasoned integrated transformer supplier, I’ve witnessed firsthand the importance of achieving the right self – resonance frequency in various applications. In this blog, I’ll share my insights on how to design an integrated transformer to meet a specific self – resonance frequency. Integrated Transformer<\/a><\/p>\n

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Understanding the Basics of Self – Resonance Frequency<\/h3>\n

Before delving into the design process, it’s crucial to understand what self – resonance frequency is. The self – resonance frequency of a transformer is the frequency at which the inductance and capacitance of the transformer form a resonant circuit. At this frequency, the impedance of the transformer reaches a maximum or minimum value, depending on the circuit configuration. This property is essential in applications such as wireless power transfer, radio frequency (RF) circuits, and power converters.<\/p>\n

The self – resonance frequency ($f_0$) of a transformer can be calculated using the formula:<\/p>\n

$f_0=\\frac{1}{2\\pi\\sqrt{LC}}$<\/p>\n

where $L$ is the inductance of the transformer and $C$ is the parasitic capacitance. This formula shows that the self – resonance frequency is inversely proportional to the square root of the product of inductance and capacitance. Therefore, to achieve a specific self – resonance frequency, we need to carefully control the values of $L$ and $C$.<\/p>\n

Design Considerations<\/h3>\n

Inductance Calculation<\/h4>\n

The inductance of an integrated transformer depends on several factors, including the number of turns, the core material, and the geometry of the windings. To calculate the inductance, we can use the following formula for a solenoid – shaped inductor:<\/p>\n

$L=\\frac{\\mu N^2A}{l}$<\/p>\n

where $\\mu$ is the permeability of the core material, $N$ is the number of turns, $A$ is the cross – sectional area of the core, and $l$ is the length of the core.<\/p>\n

When designing an integrated transformer, we can adjust the number of turns to achieve the desired inductance. Increasing the number of turns will increase the inductance, but it may also increase the parasitic capacitance and resistance. Therefore, a balance needs to be struck between the inductance and other electrical properties.<\/p>\n

Parasitic Capacitance Reduction<\/h4>\n

Parasitic capacitance is an inevitable part of any transformer design. It is mainly caused by the capacitance between the windings and between the windings and the core. To reduce the parasitic capacitance, we can use several techniques:<\/p>\n

    \n
  1. Winding Layout<\/strong>: Adopt a proper winding layout, such as interleaved winding or layer – by – layer winding. Interleaved winding can reduce the capacitance between the windings by increasing the distance between the turns of different windings.<\/li>\n
  2. Shielding<\/strong>: Use shielding materials to reduce the capacitance between the windings and the core. A grounded shield can effectively isolate the electric field and reduce the parasitic capacitance.<\/li>\n
  3. Core Selection<\/strong>: Choose a core material with low dielectric constant to reduce the capacitance between the windings and the core.<\/li>\n<\/ol>\n

    Core Material Selection<\/h4>\n

    The core material plays a crucial role in determining the performance of the integrated transformer. Different core materials have different magnetic properties, such as permeability, saturation flux density, and core loss. When designing a transformer for a specific self – resonance frequency, we need to choose a core material that can provide the required inductance and minimize the core loss at the operating frequency.<\/p>\n

    Some common core materials for integrated transformers include ferrite, powdered iron, and laminated cores. Ferrite cores have high permeability and low core loss at high frequencies, making them suitable for RF applications. Powdered iron cores have good saturation characteristics and are often used in power converters. Laminated cores are commonly used in low – frequency applications due to their low eddy – current losses.<\/p>\n

    Design Steps<\/h3>\n

    Step 1: Define the Requirements<\/h4>\n

    The first step in designing an integrated transformer is to define the requirements, including the desired self – resonance frequency, the power rating, the operating frequency range, and the voltage and current levels. These requirements will guide the subsequent design process.<\/p>\n

    Step 2: Select the Core Material<\/h4>\n

    Based on the requirements, select a suitable core material. Consider factors such as permeability, saturation flux density, core loss, and cost. Conduct experiments or simulations to evaluate the performance of different core materials.<\/p>\n

    Step 3: Calculate the Inductance<\/h4>\n

    Using the formula for inductance calculation, determine the number of turns and the core geometry to achieve the desired inductance. Consider the trade – off between inductance and other electrical properties, such as parasitic capacitance and resistance.<\/p>\n

    Step 4: Design the Winding Layout<\/h4>\n

    Design the winding layout to reduce the parasitic capacitance. Use techniques such as interleaved winding or layer – by – layer winding. Consider the physical constraints of the integrated circuit and the manufacturing process.<\/p>\n

    Step 5: Simulate and Optimize<\/h4>\n

    Use electromagnetic simulation software to simulate the performance of the designed transformer. Analyze the self – resonance frequency, impedance, and other electrical properties. Optimize the design by adjusting the parameters such as the number of turns, the core geometry, and the winding layout.<\/p>\n

    Step 6: Prototyping and Testing<\/h4>\n

    Build a prototype of the integrated transformer based on the optimized design. Test the prototype to verify the performance, including the self – resonance frequency, the power transfer efficiency, and the electrical characteristics. Make adjustments to the design if necessary.<\/p>\n

    Case Study<\/h3>\n

    Let’s consider a case where we need to design an integrated transformer for a wireless power transfer system with a self – resonance frequency of 13.56 MHz.<\/p>\n

    First, we select a ferrite core material due to its high permeability and low core loss at high frequencies. We calculate the required inductance using the formula $f_0=\\frac{1}{2\\pi\\sqrt{LC}}$, assuming a parasitic capacitance of $10$ pF.<\/p>\n

    $L=\\frac{1}{(2\\pi f_0)^2C}=\\frac{1}{(2\\pi\\times13.56\\times10^6)^2\\times10\\times10^{-12}}\\approx13.2$ $\\mu$H<\/p>\n

    Next, we design the winding layout using interleaved winding to reduce the parasitic capacitance. We use electromagnetic simulation software to optimize the design, adjusting the number of turns and the core geometry.<\/p>\n

    After building the prototype, we test it and find that the self – resonance frequency is close to the desired value of 13.56 MHz. We also measure the power transfer efficiency and find that it meets the requirements of the wireless power transfer system.<\/p>\n

    Conclusion<\/h3>\n

    <\/p>\n

    Designing an integrated transformer for a specific self – resonance frequency requires a thorough understanding of the electrical properties of the transformer and the application requirements. By carefully selecting the core material, calculating the inductance, reducing the parasitic capacitance, and optimizing the design through simulation and testing, we can achieve the desired self – resonance frequency.<\/p>\n

    Substation Transformer<\/a> As an integrated transformer supplier, we have the expertise and experience to design and manufacture high – quality transformers that meet your specific requirements. If you are interested in purchasing integrated transformers for your applications, we invite you to contact us for further discussion and negotiation. Our team of experts will be happy to assist you in finding the best solution for your needs.<\/p>\n

    References<\/h3>\n