The first ASIL C safety grade magnetic field current sensor for electric vehicle powertrains

     For today's and the next generation of inverter and battery management system designs, engineers face significant challenges to achieve higher safety goals under the new Automotive Safety Integrity Level (ASIL) requirements. To this end, Allegro MicroSystems announced the introduction of a prototype ACS37601 magnetic field and current sensor with ASIL C safety rating, high accuracy and superior accuracy for power traction, auxiliary inverters and battery management systems in electric vehicles (EVs).

     To enable customers to meet these new safety requirements while improving system efficiency and extending battery life, Allegro has developed the ACS37601 programmable Linear Hall Effect current sensor IC with overcurrent and overheat protection as well as self-checking capabilities. The ACS37601 is designed to achieve high precision and high resolution sensing without affecting bandwidth. It is Allegro's magnetic field current sensor with the highest accuracy, suitable for measuring current applications greater than 200A.

     "Allegro's ACS37601 enables our applications such as BMS and electric vehicle traction inverters current sensors to meet functional safety and precision requirements in the electric transportation (e-mobility) industry," said Julio Urrea, Vice President of Business Development at Littelfuse. Littelfuses is a diversified industrial application technology company that serves electronics, transportation and multiple industrial markets for a sustainable, connected and safer world.

    The ACS37601, which can be used with C-core, is the first ASIL C-rated magnetic field current sensor to achieve sensitivity error of 0.8% and offset error of less than 5mV across the entire vehicle temperature range, and noise reduction of 30% compared to the original device, making it ideal for battery management applications. With high operating bandwidth from DC to 240 kHz and fast response time of 2μs, the ACS37601 enables higher performance for applications such as DC battery charging and high-frequency automotive inverters. The ACS37601 uses a 5V or 3.3V power supply, enabling the use of state-of-the-art microprocessors without the need for additional components.

     Shaun Milano, Director of Allegro's Current Sensor Business Unit, said: "Littelfuse has a remarkable history as an automotive supplier capable of covering all markets around the world. "We are pleased to partner with Littelfuse to provide industry-leading field-current sensor accuracy and safety for electric vehicle powertrain applications."

     To help designers achieve state-of-the-art ASIL-compliant battery management and inverter systems, ACS37601 samples are currently available in an extremely thin (1 mm thick), 4-pin single-plug in-line package (SIP) known as the KT package. The KT package has linear pins (suffix TN) and lead molding options (suffix TH) to support surface mounting assembly and high tolerance to mechanical vibration. ACS37601 package is lead free (Pb) and uses 100% mist tin plating lead frame.