Chip ferrite beads first to achieve 20 A rating

New Products |
By Jean-Pierre Joosting

Murata has introduced the BLE32SN series of chip ferrite beads, which claim to be the first chip-type noise suppression components to have a 20-A current rating. The chip ferrite beads will be used to provide noise suppression in circuits with large current flows, such as the battery charging systems and powertrains in electric vehicles (EVs), as well as in industrial equipment.

Previously there was no chip-type noise suppression filter that could attain a 20-A current rating. This meant that multiple chips had to be mounted in parallel, which added to the bill-of-materials (BoM) costs and took up valuable board real estate. By specifying Murata’s BLE32SN series of chip ferrite beads, a much smaller number of chips will be required — enabling space savings and weight reductions.

By leveraging advanced structural simulation techniques, Murata engineers have been successful in creating a proprietary internal electrode design. This increases the electrode volume of these chip ferrite beads, compared with those using a conventional arrangement — resulting in a significant lowering of their DC resistance characteristics. Consequently, heat generation is reduced, so less thermal management is needed — allowing further cost and weight savings to be benefitted from.

Murata’s BLE32SN series ferrite beads have a compact form factor, with dimensions of 3.2- x 2.5- x 2-mm. The chip ferrite beads are capable of supporting an operational temperature range of -55°C to +125°C or -55°C to +150°C, depending on customers’ application requirements.

Also, recently, Murata announced the MRD series of open-loop current sensors for industrial systems. Each sensor integrates high-performance tunnel magneto-resistive (TMR) elements — enabling precision measurement with regard to both DC and AC currents up to 40-A, as well as maintaining stable characteristics across an extensive temperature range. This gives them an industry-leading full scale output accuracy of ±1.0% when operating anywhere between −40°C and 105°C, with fast-response time of 0.5 µs (typical) also being supported.

The coreless structure of these current sensors does not exhibit hysteresis effects or saturation issues which are typical side-effects with an iron core. It also results in reduced size and weight, as well as making mounting easier. Their proprietary differential measurement with two TMR-based elements gives immunity against external magnetic stray fields — making them suitable for use in application environments with high levels of electromagnetic noise.

Because of the high accuracy current sensing capabilities of the Murata MRD series and the fast response that these devices can achieve, they will be of significant value in a wide variety of applications. These include photovoltaic inverters, DC-DC converters, EV charging infrastructure.

MRD current sensors are compliant with the UL62368-1 electrical equipment safety standard. These devices are supplied in SOICW16 packages as well as galvanic isolation over 4.8 kV.


Linked Articles
eeNews Embedded