Overview

The OFN Series by Tamura Corporation comprises nano-crystalline core common mode choke coils designed for noise reduction in various electronic applications. These components are suitable for single-phase and three-phase systems and are optimized for PCB mounting in vertical or horizontal orientations.

Application Fields

• Uninterruptible Power Supplies (UPS)
• Solar Power Inverters
• Air Conditioning Systems
• Active Power Filters (APF) / Static Var Generators (SVG)
• Power Factor Correction (PFC) Rectifiers
• Electric Vehicles (EV) / Hybrid Electric Vehicles (HEV)
• Energy Storage Batteries

Key Features

• Use of nano-crystalline cores for high permeability and effective broadband noise reduction.
• Class B insulation rating, supporting operating temperatures from -40°C to +130°C.
• Compact sizes with various dimensions to suit different current ratings and applications.
• PCB mounting with recommended hole diameters specified per model.
• High insulation resistance (>100 MΩ at 500 Vdc) and withstand voltage (>2 kVac for 1 minute).
• Low DC resistance and high impedance at 100 kHz for effective noise suppression.

Product Specifications and Models

The series includes multiple models differentiated by inductance, rated current, dimensions, and electrical characteristics. Models are categorized into single-phase and three-phase types with detailed specifications:

Electrical Characteristics

• Inductance: Ranges from 0.8 mH to 7.5 mH minimum at 100 kHz.
• Rated Current: From 5 A up to 90 A depending on model.
• DC Resistance: Typically from 2.5 mΩ to 25 mΩ, with maximum values specified per model.
• Impedance: Measured at 1 V and 100 kHz, ranging from approximately 1.1 kΩ to over 22 kΩ.
• Dimensions: Various sizes such as 36x24x34 mm, 44x29x44 mm, 50x35x52 mm, and 65x50x65 mm.
• Weight: From 45 g to 240 g depending on size and model.

Insulation and Safety

• Class B insulation material rated for 130°C operation.
• Insulation resistance tested with EXTECH 7142 at 500 Vdc, exceeding 100 MΩ.
• Dielectric withstand voltage tested at >2 kVac for 1 minute with leakage current less than 2 mA.
• Clearance and creepage distances maintained at 2.0 mm minimum between terminals.

Mechanical and Mounting Details

• Recommended PCB hole diameters vary by model, typically from Φ1.3 mm to Φ2.9 mm.
• Mounting includes soldering and adhesive bonding for secure installation.
• Detailed external dimension drawings provided for each model to assist in PCB design.

Performance Characteristics

Graphs and data illustrate inductance and impedance behavior over frequency ranges from 0.001 kHz to 10,000 kHz, demonstrating stable inductance and high impedance at noise-relevant frequencies.

Notes and Recommendations

• Specifications are subject to change; users should verify current data before design.
• Operating temperature range is -40°C to +130°C; storage temperature range is -40°C to +85°C.
• Models are designed for effective noise suppression in high-frequency switching environments.
• Selection of model should consider rated current, inductance, and physical size constraints.

Confidentiality

All rights reserved by Tamura Corporation. The information is confidential and proprietary.