Toroidal Common Mode Chokes
The TRF series common-mode choke is designed for common-mode noise suppression in AC/DC and DC/DC power lines. It offers a maximum common-mode impedance of 2240Ω and inductance of 1000µH. The product uses nanocrystalline or ferrite cores. The rated current is up to 35A, with DCR as low as 1.5mΩ, effectively reducing power loss. Isolation voltage is up to 2500Vrms, ensuring safe high-voltage isolation. The operating temperature range is -40°C to +125°C, meeting various harsh environment requirements. Electrical specifications are based on testing at 25°C. Rated current is defined as the reference value at which the winding series connection causes a 40°C temperature rise. It is widely used in switching power supplies, industrial equipment, communication power supplies, AC/DC converters, and DC/DC converters.
Features
- Common-mode impedance – up to 2240Ω
- Inductance – up to 1000µH
- Rated current – up to 35A
- DCR – as low as 1.5mΩ
- Isolation voltage – up to 2500Vrms
- Nanocrystalline / ferrite core – optional
- Operating temperature – -40°C to +125°C
- RoHS compliant
Product Specification Selection Table
| Model | Common-Mode Impedance (Ω) | Impedance Frequency | Inductance (μH) | Isolation Voltage (Vrms) | Core Material | Weight (g) |
|---|
| TRF3923-30431 | 3150 @2.2MHz | 2.2MHz | 300 | 2500 | Ferrite | 53.66 |
| TRF3921-10534 | 1440 @10MHz | 10MHz | 1000 | 2500 | Nanocrystalline | 51.70 |
| TRF7018-10535 | 1040 @8.2MHz | 8.2MHz | 1000 | 2500 | Nanocrystalline | 107.40 |
| TRF7036-75433 | 2240 @4.4MHz | 4.4MHz | 750 | 3250 | Nanocrystalline | 223.17 |
Applications
- AC/DC power line noise suppression
- DC/DC converter filtering
- Switching power supply (SMPS) EMI filtering
- Industrial equipment power supplies
- Communication equipment power supplies
- Automotive electronic systems
- Computer peripheral power supplies
- EMI/RFI suppression
FAQ
Q: What are the advantages of nanocrystalline cores compared to ferrite cores?
A: Nanocrystalline cores offer higher magnetic permeability and lower core loss, providing higher common-mode impedance in the same volume, with lower loss at high frequencies. Ferrite cores are more cost-effective. The TRF series offers both core material options depending on the model.
Q: What applications are the 2500Vrms and 3250Vrms isolation voltages suitable for?
A: The 2500Vrms isolation voltage is suitable for most industrial AC/DC and DC/DC power supply applications, meeting basic safety isolation requirements. The 3250Vrms (TRF7036 series) is suitable for applications with higher safety isolation requirements, such as medical equipment, high-voltage power supplies, and automotive electronics.
Q: What customisation options are available for this product?
A: Customisation of inductance value, turns ratio, pin configuration, and package size is supported. Please contact our technical sales team with your specific requirements.
Q: How long is the delivery time and what packaging methods are used?
A:The standard lead time is 2-8 weeks after order confirmation, depending on product specifications and order quantity. Products are securely packed with cartons, foam, pallets, wrapping film, and fixing straps to ensure safe international transportation.
