Melexis introduces Triphibian digital output pressure sensor chip

     Melexis has announced the introduction of the MLX90834 pressure sensor chip, designed for demanding automotive applications such as electric vehicle thermal management, further enriching its Triphibian™ family of products. This reliable, factory-calibrated MEMS solution accurately measures pressures from 2 to 70bar in both gas and liquid media. Its digital SENT output provides absolute pressure, diagnostic, and temperature information to help the system achieve greater performance and reliability.

     The core competence of the MLX90834 is derived from Triphibian™ technology, which is unique to Millicore. The technology ensures the ability to perform accurate pressure measurements in gas and liquid media, even in high-pressure environments up to 70bar, through an innovative MEMS sensor design. This versatility is achieved through the unique beam arm and tip sensing membrane structure, cleverly packaged in a compact SO16 package.

     In the heat pump system of electric vehicles, it is very important to accurately monitor the pressure and temperature of the refrigerant. To effectively avoid damage to expensive components in the system, liquid media must be prevented from entering the compressor. Therefore, the system must ensure that the refrigerant remains in a fully superheated gas state when it reaches the evaporator outlet. This can be achieved by precisely monitoring the pressure and temperature between the evaporator and the compressor in the same location, allowing the system to precisely calculate and regulate the degree of overheating of the fluid using intelligent expansion valves.

     The MLX90834 uses Triphibian™ technology and is equipped with a digital SENT output to provide accurate pressure and temperature data to the system. The product supports external NTC and is factory calibrated to ensure better than ±1 ° C measurement accuracy over a wider temperature range. Accurate pressure measurements can be used to derive the equivalent temperature when the medium is saturated (liquid and gas co-exist in the evaporator), while NTC provides the actual temperature of the fluid.

     The introduction of MLX90834 provides strong support for the manufacture of heat pump components such as intelligent expansion valves. By embedding this digital sensor chip into heat pump components such as valves, manufacturers can develop smart valves with edge computing capabilities. With Melai's deep expertise in sensing and drive technology, its motor driver chips can efficiently process the data provided by the MLX90834. This fusion measurement technology enables heat pump manufacturers to integrate system adjustment functions directly into the components, greatly increasing the overall value of the product: These locally controlled intelligent expansion valves have higher pressure and temperature sensing accuracy, effectively reducing overheating in the operation of the heat pump system, thereby improving the overall operating efficiency of the system.

     The MLX90834 has a built-in sensor signal processing circuit, digital hardware, voltage regulator and digital output driver chip. A piezoresistive element implanted in the sensing membrane can form a Wheatstone bridge to sense the pressure signal. The signal is amplified and converted into a digital signal, temperature compensated by 16-bit digital signal processing (DSP), and finally output in digital (SENT) mode.

     The sensor chip incorporates an advanced voltage protection mechanism that effectively resizes overvoltage (above +40V) and reverse voltage (below -40V), making it suitable for automotive and truck applications. In addition, the MLX90834, as an ISO 26262 compliant stand-alone safety Unit (SEooC), supports ASIL Class C system integration and is fully compliant with the latest EV safety standards.

     Laurent Otte, Melexis Product Line Director, said: "The MLX90834 is a major breakthrough for our team based on Triphibian™ technology, which is not only a versatile and efficient pressure sensor product, but also an excellent performance in heat pump applications. "Our talented team of engineers, with their deep understanding and innovative application of Triphibian™ technology, successfully created a pressure sensor chip that is not only highly flexible and highly programmable, but also exhibits superior intelligence to meet and exceed our customers' increasingly diverse needs."