TDK expands compact high-current choke series ERU33 toward higher currents with new core material

September 04, 2024

TDK Corporation (TSE:6762) expanded the EPCOS ERU33 high-current chokes with the even higher-current ERU33M using a new core material. As power densities and currents in automotive and industrial applications continue to increase, this new series meets these requirements by using an alloy powder core material that exhibits a softer saturation characteristic than the core material used previously.

These shielded components for through-hole (THT) mounting are designed for saturation currents from 55 A to 120 A at +100 °C. The three new types cover a range of inductance values from 1.4 µH to 7.2 µH and DC resistances as low as 0.46 mΩ to 1.2 mΩ. Thanks to the flat wire winding, the chokes have very compact dimensions of only 33 x 33 mm and a height of 11 mm or 15.3 mm, respectively. By thermally connecting the flat coils to the electrically insulated powder alloy core, the component can be attached to a heat sink to effectively dissipate the heat. In addition to these standard types, customized versions with other inductance values can also be realized.

The RoHS-compatible and AEC-Q200-qualified inductors are designed for operating temperatures from -40 °C to +150 °C. Typical automotive applications are buck-boost chokes for DC-DC converters (e.g., for 48 V on-board power supplies or differential mode chokes in the input filter of onboard chargers) as well as medium- and high-current battery chargers and inverters. In industrial electronics, they can be used as storage and output chokes in high-current supplies, solar inverters for PV systems, and PoL (Point of Load) converters.

To become familiar with the different models of this series, TDK provides a sample kit for the ERU33M chokes (B82579X0033); it contains four of each of the three variants.

Main applications

• Energy storage chokes for DC-DC converters, VRM modules, PoL converters, and inverters in automotive and industrial applications

Main features and benefits

• High saturation currents from 55 A to 120 A
• Low DC resistances of 0.46 mΩ or 1.20 mΩ
• Very compact dimensions of only 33 x 33 mm and a height of 11 mm or 15.3 mm
• Effective heat dissipation by directly attaching a heat sink
• Easily customizable
• Qualified to AEC-Q200 Rev. E