Murata has released the BLM18KN_EH series of ferrite chip beads for noise suppression in power lines at temperatures up to 175C. Target applications are automotive equipment including engine and transmission ECUs and turbo motor controllers, with the components satisfying AEC-Q200 qualification requirements.
Demand for compact, lightweight and robust electronic control substrates grows, especially as more and more ECUs are placed closer to the engine. Previously, automotive engineers have not been able to take direct power line noise suppression measures, rather implementing them in cooler areas which problematises the design. This series of ferrite chip beads enables engineers to fulfil this design challenge.
By choosing a ferrite material that does not lose its magnetic properties at high temperatures and an electrode to suppress temperature-related deterioration, the series conforms to the AEC-Q200 standard for use up to 175C. Removing design stress for high-temperature areas removes the necessity to review the mission profile. Energisation is possible at 150C, which improves the degree of design freedom. A further benefit of the new series is its low DC resistance, which decreases heat generated and therefore increases efficiency.
The new chip beads are offered in 0603-inch size with dimensions down to 1.6mm x 0.8mm. The devices have low direct current resistance (Rdc) for compatibility with large currents, optimal for low power consumption. Over the broad operating temperature range, the rated current is from 740mA to 4,000mA (-55C to +125C), 490mA to 2,600mA (+150C) and 10mA (+175C). The typical impedance at 100 MHz ranges from 26Ohm to 1000Ohm.