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EF20 12V 24V 25W Flyback Transformer For LED Driver And Medical Power Supply
Place of Origin:
China
Brand Name:
Chipsen
Certification:
UL/CUL/ISO9001/ISO14001/RoHS/Reach/IATF16949
Model Number:
EF20
Minimum Order Quantity:
1000
Price:
US$0.15-1.5
Packaging Details:
Carton 1: 25.5 X 21.5 X 21cm Carton 2: 43.5 x 24.5 x 21 cm
Delivery Time:
3-4 Weeks
Payment Terms:
T/T
Supply Ability:
10000000/Month
Inquiry Now
Get A Quote
Specifications
Highlight Features
EF20 flyback transformer
,12V flyback transformer
,25W flyback transformer frequency
Product Name:
EF20 Transformer
Frequency:
1KHz-1MHz
Core Material:
PC40/PC44/PC95 Ferrite Core
Winding Material:
UL Approved Pure Copper Transformer
Input Voltage:
5V-480V
Output Voltage:
12V 24V 48V 60V 120V 240V
Operating Temperature:
-40~265
Power:
1W-30W
Mounting Type:
Horizontal/ Vertical/ PCB Mount
Warranty Period:
5 Years
Product Description
Customized High Frequency EF20 Ferrite Core Transformer 12V 24V 25W Flyback Transformer for LED Driver and Medical Power Supply
Product Introduction
The EF20 High-Frequency Transformer (also known as EF20/20) is a high-performance magnetic component engineered for mid-range Switch Mode Power Supply (SMPS) systems. Designed to handle power outputs typically ranging from 15W to 30W, the EF20 serves as an ideal upgrade from smaller EE-series transformers. Its optimized core geometry provides a larger winding window and a flatter profile, making it the preferred choice for engineers seeking a balance between high power density and efficient thermal management in compact electronic assemblies.
| Parameter | Typical Value / Spec |
|---|---|
| Core Type | EF20 / EF20/20 (Ferrite Core) |
| Mounting Type | Vertical / Horizontal PCB Mount |
| Pin Count | 8-Pin / 10-Pin / 12-Pin (Customizable) |
| Dimensions | Approx. 20.0mm x 20.0mm x 15.5mm (Excl. pins) |
| Power Output | 10.0W - 30.0W (Typical) |
| Operating Frequency | 50KHz - 300KHz |
| Input Voltage | 85V - 265V AC / 100V - 400V DC |
| Hi-Pot (Isolation) | 3.0KV - 3.75KV AC / 1min |
| Insulation Resistance | >=100MΩ (at 500V DC) |
| Leakage Inductance | < 2% - 4% (Typical) |
| Core Material | PC40 / PC44 / PC95 Mn-Zn Ferrite |
| Winding Wire | 100% Pure Copper (2UEW/3UEW/TIW) |
| Insulation Class | Class B (130°C) / Class F (155°C) |
| Ae (Effective Area) | 32.2 mm² |
| Operating Temp | -40°C to +125°C (Incl. Temp Rise) |
| Storage Temp | -25°C to +85°C |
| Compliance | RoHS, REACH, UL Recognized (Optional) |
Technical FAQ for EF20 Transformers
Q1: How does the "Flat-Top" core geometry of the EF20 improve thermal reliability in 25W continuous-load applications compared to a smaller EE-series core?
A: The EF20 (EF20/20) core is specifically designed with a wider and flatter surface profile, which offers a significantly higher Surface-Area-to-Volume ratio than smaller cores like the EE19. In a 25W continuous-load environment—such as an LED driver—this increased surface area enhances Natural Convection Cooling, allowing heat to escape more efficiently from the core and windings. By maintaining a lower operating temperature, the transformer avoids reaching the Curie point of the ferrite material, preventing Thermal Runaway and ensuring that the inductance remains stable over long-term operation. Furthermore, using high-tier materials like PC95 allows the EF20 to achieve its minimum power loss at 100°C, perfectly aligning with the typical thermal profile of enclosed power modules.
Q2: What winding strategies can be implemented within the EF20's wide winding window to minimize Leakage Inductance (Lk) for high-efficiency DC-DC converters?
A: The EF20 core provides a relatively large winding window compared to its height, which is an ideal characteristic for reducing parasitic effects. To achieve a leakage inductance of < 2%, we recommend the following strategies:
- Sandwich Winding (Primary-Secondary-Primary): By splitting the primary into two layers and sandwiching the secondary in between, the magnetic coupling is maximized, significantly reducing Lk.
- Utilization of Window Width: The EF20's width allows for fewer layers to achieve the required turns. Reducing the number of layers decreases the Proximity Effect and AC copper losses, which is critical for converters operating at frequencies above 100kHz.
- Triple Insulated Wire (TIW): For designs requiring high safety isolation, using TIW for the secondary winding eliminates the need for bulky margin tapes. This allows the windings to occupy the full width of the bobbin, further tightening the coupling and improving overall efficiency by reducing the energy lost to switching spikes.
Product Features
- Optimized EF Geometry: The flatter E-core design offers a wider winding window, facilitating the use of thicker wire or multiple outputs without significantly increasing the component's height.
- Extended Frequency Support: Optimized for efficient operation at high switching frequencies, typically between 50kHz and 300kHz, supporting high-efficiency conversion across various topologies.
- Premium Ferrite Materials: Constructed using high-permeability Mn-Zn ferrite cores (such as PC44 or PC95), which ensure low power loss and stable performance even at elevated temperatures.
- Flexible Pin Configurations: The standard EF20 bobbin supports versatile pin counts (up to 10 or 12 pins) in both Vertical and Horizontal orientations to accommodate complex PCB layouts.
- High Insulation Integrity: Designed to meet global safety standards, utilizing UL94-V0 rated flame-retardant bobbins and high-grade insulation tapes for superior dielectric strength.
Product Applications
- LED Lighting Drivers: Extensively used in high-wattage LED drivers and smart lighting controllers requiring high efficiency and long-term stability.
- Medical Power Supplies: A critical component in patient monitoring and diagnostic equipment where high isolation and low noise are mandatory.
- Smart Meters & Industrial Controls: Provides reliable auxiliary power for energy meters, PLCs, and industrial automation modules.
- Communication Equipment: Powers mid-range networking hardware, routers, and Power over Ethernet (PoE) injectors.
Product Advantages
- Superior Power-to-Size Ratio: Delivers significantly higher power handling (up to 30W) than smaller series while maintaining a low-profile footprint, maximizing PCB real estate.
- Enhanced Thermal Dissipation: The EF20 core's larger surface area relative to its volume ensures better heat dissipation, preventing thermal runaway and extending the lifespan of surrounding components.
- Minimal Parasitic Effects: Precision winding limb and tight core tolerances result in exceptionally low Leakage Inductance and Stray Capacitance, improving switching efficiency and reducing EMI filter requirements.
- Stringent Safety Compliance: Fully compliant with RoHS, REACH, and CE standards, with optional UL Recognized insulation systems (up to 3.75kV AC isolation) for international market entry.
Company Strengths
Chipsen Electronics Technology Co., Ltd., established in 2000, is a specialized manufacturer of high frequency transformer, low frequency transformer, toroidal inductor, SMD power inductor, super high current inductor, choke coil and switch. Chipsen has got a good reputation in domestic and oversea markets which include North & South America, Europe and Southeast Asia.
Chipsen possesses a professional management team, as an ISO9001, ISO14001 & IATF16949 audited company, which always commits to producing environmental protection and qualified products. Our products are certified by UL Class B/Class F/Class H, CQC and RoHS, and obtained 21 patents.
These achievements mainly come from our strong R&D team, providing various solutions for temperature decreasing, noise cancellation and coupled radiation conductivity. Our products widely used in various fields of new energy, PV, UPS, Robotics, smart home, security systems, health care and communication.
Vision: To Be Global Transformer Brand Supplier
Mission: Create Values for Customers and Society, Grow with Customers and Staffs
Values: Customer First, Team Cooperation, Embrace Changes, Integrity, Creative & Happy
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