LLC is one of many switch mode topologies for power supply and battery charging. The LLC transformer is critical in determining an LLC resonant converter’s efficiency. Resonant tanks are circuits comprised of inductors (L) and capacitors (C) that oscillate at a fixed frequency known as the resonant frequency. LLC transformers have two inductors and one capacitor, a configuration that creates resonance at the switching frequency.
Here we’ll explain the pros and cons of LLC transformers, as well as their common applications.
What Is LLC Topology?
LLC is one of several switch mode topologies used in power supply and battery charging operations. The LLC transformer helps determine an LLC resonant converter’s efficiency. An LLC resonant power conversion topology reduces switching losses by enabling zero voltage switching (ZVS), which reduces needless power waste in switches. Power dissipation can be limited to as little as 2%, ensuring 98% total efficiency.
Advantages of LLC Transformers
These are some of the advantages of LLC transformers.
LLC resonant converters are extensively used in industrial applications because they can integrate two resonant elements into one transformer. This helps designers save money on construction and supplies.
Energy efficiency is critical for decreasing environmental impact while saving money. Even a 2% increase in total efficiency can significantly impact energy costs. With federal Energy Star criteria becoming increasingly stringent, LLC transformers are ideal solutions to achieve optimum efficiency.
Energy Efficiency & Sustainability
The market demands greater efficiency in server farms, LED lighting, gate automation, vending machines, battery chargers, and other areas. LLC resonant topology has an efficiency of 94-96% in the most basic circuit solutions, and it can improve further through synchronous rectification and other precautionary measures.
Compact & Effective
Compared to other topologies, LLC-LCC power supplies are smaller and have significantly lower electromagnetic interference (EMI) concerns, reducing EMI and harmonic pollution.
Aids EMI Design
It can control the output across a wide range of line and load fluctuations with very little difference in switching frequency, making basic EMI filters considerably easier to build.
Applications of LLC Transformers
LCC topology is the best choice for applications requiring a broad output voltage range, such as power supply for variable length LED strings (including deep dimming) or high-performance battery chargers.
Electronics industries rely on LLC transformers for their:
- Electrical isolation
- High energy density
- High operation frequency
- Low voltage stress
- Magnetic integration
- Wide output ranges
A precision LLC transformer is best for converters in a variety of energy-sensitive applications, such as:
- High-end audio
- Home appliances
- Industrial LED lighting
- LED/LCD televisions
Drawbacks of LLC Transformers
These are some potential drawbacks to keep in mind when working with LLC topology.
Requires Sensitive Customization
The best design of a switch mode power supply (SMPS) transformer must inevitably address the limits associated with magnetic components; otherwise, it may result in a significant drop in efficiency.
Not Suitable for Operating Voltage Variations
Resonant topologies’ major shortcoming is in applications with substantial input or output operating voltage changes.
If the tank is appropriately designed, ZVS can be maintained even in the face of relatively high voltage changes. However, the benefits are reduced compared to alternative topologies due to the negative influence on cost and performance. The magnitude of this influence is often tolerable, but it does grow generally in proportion with voltage range expansion.
Contact MPS Industries for More on LLC Transformers
MPS Industries takes pride in offering high-quality LLC transformers and other magnetic components to clients in the automotive, aerospace, military, industrial, electronics, medical, and telecommunications industries. MPS is committed to meeting and surpassing client expectations as a leading manufacturer of standard and custom electronic components like transformers, common mode chokes, inductors, power supplies, and current sensors. Our strict quality management system and ISO certifications demonstrate our dedication to quality.
Choke vs. Inductor: What’s the Difference?
At MPS Industries, we specialize in manufacturing high-quality magnetic parts for automotive, medical, power distribution, and more. We’re ISO 9001:2015 certified, and we prioritize quality engineering practices to create products our clients can trust in critical applications, including inductors and chokes.
Both chokes and inductors can deliver and modify electrical current. However, inductors are generally used to sense, filter, or transform electrical current. They store that energy as a magnetic field around their inbuilt insulated coil. Chokes, on the other hand, are a specific type of inductor that restricts the flow of high-frequency AC and only allows DC through to downstream parts within an electrical system. Learn more about the differences between the two and how to determine the best fit for your needs.
What Is a Choke?
Chokes, a subtype of an inductor, are designed to restrict or control the flow of electrical current passing through its coil and core, which consists of a magnetic core wrapped in a wire insulated coil or a donut-shaped ferrite bead strung on a wire. Primarily, they prevent the flow of alternating current (AC). This component ensures only direct current (DC) passes through and reaches subsequent components. Because of this core functionality, chokes are typically used for protection. If they precede insulative components, they can increase the insulation’s longevity by blocking high-frequency alternating currents and sharp fluctuations in current levels. Chokes only allow a flow of more controllable (and thereby less damaging) current to pass through. They can also act as a check on certain systems.
Chokes can be designed for optimal performance in different types of environments, such as high-speed applications, circuits with next to no grounding components, electrical circuitry that may face disruption from noise, signal mixing, and other complications. They’re also commonly used in power supplies and direct current power lines.
What Is an Inductor?
Inductors represent a wide array of different electrical components that can change, filter, store, and otherwise interact with electrical current. While chokes can restrict current and protect downstream components from overload, inductors are also valued for their storage capabilities. They also have a magnetic coil, which, properly energized by electrical current, generates and holds a magnetic field. These components can be large, often the largest component in a circuit, and can come in a wide range of shapes and sizes to meet the needs of a specific electrical system.
Common use cases for inductors include:
- Filters: Inductors can restrict the flow of current and allow only certain ranges of electricity through to downstream components.
- Energy storage: Inductors store energy by generating and holding a magnetic field.
- Transformers: Inductors can be combined to create a transformer which transfers energy from one to subsequent multiple or singular circuits. They can change the voltage as the electricity is transferred from circuit to circuit, but the frequency won’t change.
- Motors: Inductors convert electrical and magnetic energy into physical motive force.
- Sensors: Inductors detect changes in electrical current through its impact on the inductor’s magnetic field.
Chokes vs. Inductors: The Main Differences
Because chokes and inductors share many core attributes and applications, it can be difficult to know which one best serves a specific application. The key differences between chokes and inductors are:
- Magnetic Field: Inductors can generate and hold magnetic fields as a form of temporary energy storage, often to switch power supplies and energizing circuits. Chokes do not.
- Purpose: Chokes remove AC and only allow DC to filter through. Inductors can also provide this functionality, along with signal filtering; however, the inductor is then considered a choke when used for that purpose.
Before choosing the component for your design or system, determine its primary function and then select the best inductor or choke for those circumstances.
Chokes and Inductors From MPS Industries
When choosing high-quality electrical components, it is critical to know which components best serve your application. MPS Industries is a leading provider of inductors, chokes, and other electrical components that manufacturers can trust in their products and installations. Contact us today to learn more about our selection of inductors and chokes, as well as our manufacturing capabilities.