TDK Electronics · TDK Europe

High-Current Ring Core Chokes

EMC for Input and Output / DC Link

TDK CeraLink capacitors

Electrical and electronic equipment generates common-mode interference. In order to meet the safety requirements within the leakage current limits, chokes with a high asymmetrically effective inductance must be used. Common-mode chokes with a closed core topology are especially suitable for this purpose.


  • Glueless design for most parts
  • Open design for improved thermal performance and cooling
  • Voltages up to 1000 V
  • Insulation System Class155 (F) to UL 1446 applicable (most parts) 
  • Especially B8272*V2*U*: suitable for household appliances (white goods) in accordance with tightened EN 60335-2-xx standards

Product Line-Up


Double chokes


Triple chokes


Quadruple chokes


DC Input, AC In-/Output 1-phase

AC In-/Output 3-phase

AC In-/Output 3-phase + N

Rated current I[A]

6 ... 56

8 ... 62

12 ... 26

Nominal inductance L[mH]

0.12 ... 7.8

0.35 ... 6.2

0.43 ... 1.45

Rated voltage

250 V AC

440/250 V AC

500/300 V AC

250 V AC

750 V DC

480/275 V AC

300 V AC

500/300 V AC

300 V AC

700 V DC

520/300 V AC

600 V AC

1000 V DC

550/320 V AC

600/350 V AC

690/400 V AC

Core Size

R26 ... R50

R42 ... R80


*Customer-specific adjustments are possible based on our flexible platform concept. 


Magnetic Flux

The problem of core material saturation due to the operating current which is depending on the working temperature solved in these designs by winding two coils with an equal number of turns on the core. These coils are connected in such a way that the magnetic flux induced by the upper coil is compensated by the lower coil.

Main and Typical Applications

Consumer applications: refrigerators (compressor), air-conditioners (compressor & fan motor), dish-washers (water pump) and vacuum cleaners (motor drive).

Industrial applications: cooling fans and compressors, circulation pumps for cooling and heating systems and general motor drives i.e. conveyor belts, elevator and sliding doors.

Suitable for

 Solar Inverters

Get data sheets and search

PDF Design Inductance (mH) Rated current (A) Rated temperature (°C) Rated voltage (V AC) Rated voltage (V DC) Number of lines Type
Current-compensated ring core choke 1 - 6.25 10 - 17 70 250 --- Double B8272*V2*U*
Current-compensated ring core choke 1.4 - 7.8 6 - 13 60,  70 250 --- Double B82725S2*
Current-compensated ring core choke 0.42 - 3.3 20 - 50 70 600 1000 Double B8272xE6
Current-compensated ring core choke 1.4, 2.2 16 60 250 --- Double B82726S2163
Current-compensated ring core choke 1.7 25 70 300 550 Double B82726S3223A340
Current-compensated ring core choke 2.2, 3.3 10, 12 85 250 750 Double B82726S61*3
Current-compensated ring core choke 0.75, 1.6 20, 24 60 250 --- Double B82726S22*3
Current-compensated ring core choke 1.3 18 50 250 --- Double B82726S2183
Current-compensated ring core choke 0.19 54 75 300 700 Double B82726S3543
Current-compensated ring core choke (quad) 0.43 - 1.45 12 - 26 70 500/300 --- Quad B82767S4
Current-compensated ring core choke (triple) 3.2, 6.2 8, 13 70 550/320 --- Triple B82746S
Current-compensated ring core choke (triple) 0.8 50 60 520/300 --- Triple B82748S4503
Current-compensated ring core choke (triple) 0.82, 0.85 30, 35 70 500/300 --- Triple B82747S4
Current-compensated ring core choke (triple) 0.35 12 85 440/250 --- Triple B82745S6123
Current-compensated ring core choke (triple) 1.7, 2 10 70 500/300,  520/300 --- Triple B82746S4103A02*
Current-compensated ring core choke (triple) 1.5 23 40 690/400 --- Triple B82748F6233
Current-compensated ring core choke (triple) 1.1 62 40 690/400 --- Triple B82748S6623
Current-compensated ring core choke (triple) 1.8 18 70 440/250 --- Triple B82747S4183
Current-compensated ring core choke (triple) 0.75, 1.15 20 70 500/300 --- Triple B82746S4
Current-compensated ring core choke (triple) 1.3 20 60 520/300 --- Triple B82747S4203A
Current-compensated ring core choke (triple) 0.57 - 2.2 16 - 35 70 600/350 --- Triple B82747E6
Current-compensated ring core choke (triple) 0.95 31 70 440/250 --- Triple B82747S6313
Current-compensated ring core choke (triple) 1.5 42 50 440/250 --- Triple B82747S4423
Current-compensated ring core choke (triple) 1.5 18 40 480/275 --- Triple B82748F4183

In order to download up to 20 files together as zip, please mark them with the check box. To start the download, please click the Download button at the end of the list.

  • General technical information
  • EMC services
  • Quality and environment
  • Cautions and warnings
  • Symbols and terms
  • I core chokes: General
  • Ring core chokes with iron powder core: General
  • Sine-wave chokes: General
  • Current-compensated chokes: General

In order to download up to 20 files together as zip, please mark them with the check box. To start the download, please click the Download button at the end of the list.


Frequently Asked Questions

Why are common mode chokes necessary?

Common mode chokes are used in EMI filtering circuits to help achieve electromagnetic compatibility (EMC). They do this by suppressing conducted noise, which is common in all types of power transmission and power lines.

As there is often no marking to indicate the winding direction (polarity) on common mode chokes, is operation impacted if the winding on the chokes are not aligned when mounted?

The mounting direction has no impact on the operating characteristics of common mode chokes.

Do common mode chokes generate heat?

They do generate heat, it is in proportion to the power. The amount of power flowing is calculated using the standard I2 x R equation, where R is the DC resistance of the common mode choke for a DC current, or the RMS value of an AC current. EMI chokes are designed to suppress high-frequency noise, and there is no significant loss introduced by this noise into the core or windings that might contribute to the heat generated.

What is the difference between common mode and differential mode?

Common mode refers to signals or noise flowing in the same direction in all lines. Differential (normal) mode refers to signals or noise flowing in opposite directions in a pair of lines.

To explain further, consider the configuration shown below, in which two copper wires are wound on a ferrite ring core. In this structure, two patterns can exist: one with currents flowing in the same direction (common mode), and another with currents flowing in opposite directions (differential mode).

 4 FAQ pic

Can a common mode choke withstand more than its rated current, if applied for a short period of time?

Although it depends on the magnitude of the current and the time period during which the current is applied, our products are not covered under warranty when used with a current that is higher than the rated current at a specific ambient temperature.

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