EDR Series High‑Frequency Transformers: Low‑Profile Design for High Power Density

The global push toward higher power density and miniaturization in electronic systems is reshaping the magnetic component industry. At the heart of this transformation lies the EDR series of high‑frequency transformers—a low‑profile ferrite core design that combines compact size, excellent magnetic shielding, and high power handling capability for demanding power electronics applications.

Technical Specifications

Features

• Low profile construction -- Enables integration into space‑constrained PCB layouts.
• Excellent magnetic shielding -- Minimizes electromagnetic interference (EMI) and crosstalk.
• High power in small volume -- Achieves output power up to 800 W while maintaining a compact footprint.

Design and Technical Foundation

EDR series transformers are built around a planar ferrite core architecture, utilizing E‑type, EC, ETD, EER, PQ, or RM core geometries. The cylindrical center column design reduces copper loss by approximately 11% compared to rectangular cross‑sections, while facilitating easier winding and improved heat dissipation. The low‑profile construction enables surface‑mount integration in space‑constrained PCB layouts.

Frequency flexibility spans from 20 kHz up to 500 kHz, while power handling ranges from 10 W up to 800 W. Thermal performance is assured across -40 °C to +125 °C operating range, with storage conditions of -25 °C to +85 °C and 30% to 95% humidity. Core material choices include PC40, PC44, PC95, and next‑generation PC95D/PC95A high‑frequency low‑loss ferrites, offering developers precise trade‑offs between cost, permeability, and core loss characteristics.

Application‑Specific Variants

The EDR series spans multiple mechanical footprints to address diverse power conversion needs:

• EDR28 -- Most popular design for LED tube lighting, supporting input voltages of 85--265 VAC and output of 4--24 VDC. Combined with PC44 core material, the EDR28 achieves efficient output in an ultra‑low profile.
• EDR39 -- Multi‑winding configuration (four windings) tailored for multi‑output switching power supplies, industrial control systems, and high‑power adapters. Features PC40 magnetic cores, low leakage inductance, high withstand voltage, and tight batch‑to‑batch consistency.
• EDR2609/2809/2810/3909 -- General‑purpose footprints for communications equipment, television power supplies, air conditioning power stages, computer power systems, and various DC‑DC converters.
• EDR3810 -- Ultra‑thin design featuring a patented bracket design enabling low‑profile PCB placement. Powered by PC95D/PC95A low‑loss ferrite cores, it achieves high efficiency while reducing manufacturing cost through fully automated production.

Performance Differentiators

Low Leakage Inductance and EMI Control

The closed magnetic circuit inherent to EDR architecture yields minimal leakage inductance and excellent magnetic shielding, significantly reducing electromagnetic interference. This is particularly critical for high‑frequency switching converters where traditional core shapes often struggle with EMI compliance. The effective shielding makes it easier to pass stringent EMC certifications without costly additional filtering stages.

Superior Thermal Management

The cylindrical center column geometry improves heat dissipation compared to traditional rectangular core designs, while the wide operating temperature range of -40 °C to +125 °C makes EDR series suitable for outdoor and industrial environments.

Compact Size, High Power Density

Despite its low profile, the EDR series delivers up to 800 W output power, making it an ideal choice for applications where PCB space is limited but high power is required --- such as LED drivers, industrial power supplies, and onboard chargers.

Quality and Compliance

Guangdong Haoer Electronics Co., LTD manufactures EDR series transformers under a full‑process quality management system from IQC to OQC. Each unit undergoes 100% electrical testing, including inductance, leakage inductance, DCR, withstand voltage (Hi‑Pot), and insulation resistance. Core materials are traceable to top‑tier suppliers with batch‑specific RoHS and REACH reports. Products are certified to UL, CE, and ISO9001 standards, with full compliance to international safety requirements for export markets.

The EDR series offers a versatile, high‑performance solution for modern power conversion challenges --- from ultra‑thin LED drivers to multi‑output industrial power supplies. With low profile construction, excellent magnetic shielding, and the ability to deliver up to 800 W in a small volume, EDR transformers provide a reliable path to smaller, cooler, and more efficient power systems.