Chip ferrite beads suppress power line noise in automobiles

Murata has announced the BLM31KN_BH series of chip ferrite beads for use in automotive powertrain safety applications with a high, guaranteed temperature capability of 150ºC.

The chip beads are aimed at the automotive market for use as noise suppression components in power line circuits.

They are to be installed in engine bays and LED headlights that require guaranteed performance at high temperatures.

Automotive market

In the automotive market, the need for noise suppression to counteract conductive and radiated noise has recently increased.

This is due to the development of motorisation of various functions including those in hybrid and electric cars.

The number of motor control circuits or inverter circuits has increased with the motorisation of powertrains.

Which require noise suppression components that are capable of dealing with large currents.

Reduce vehicle weight

Furthermore, in order to reduce vehicle weight, the ECUs for engine systems and safety systems tend to be located in engine bays.

Which reach high temperatures, and hence require noise suppression components capable of working in, and sustaining those high temperatures.

Murata has realised a product with the small package size of 3216 (3.2×1.6mm) that supports the large currents suitable for power lines (120ohm/4A at 125ºC).

By creating design specifications for internal and external electrodes for use in environments of 150ºC.

Noise suppression

Thus contributing to the creation of noise suppression designs for these power lines.

The BLM31KN_BH series conforms to the automotive test standard AEC-Q200.

Available within the range of -55 to 150 ºC with derating of the rated current.

It determines the rated current at ambient temperatures of 125 and 150ºC.

Also guarantees the specifications and reliability in environments of 150ºC.

The beads’ impedance up to 1,000ohm is effective for noise suppression at 100MHz.