Melexis Unveils Triphibian™ Digital Output Pressure Sensor Chip - Trends in de industrie

Plaats op september 12, 2024

Global microelectronics company Melexis has announced the release of the MLX90834 pressure sensor chip, designed specifically for demanding automotive applications such as thermal management in electric vehicles (EVs). This new addition expands their Triphibian™ product line. The highly reliable and factory-calibrated MEMS solution can accurately measure pressures ranging from 2 to 70 bar in both gas and liquid media. Its digital SENT output provides not only absolute pressure but also diagnostic and temperature information, enabling systems to achieve greater performance and reliability.

The MLX90834's competitive edge comes from Melexis’ proprietary Triphibian™ technology. This innovative MEMS sensor design ensures precise pressure measurement in both gas and liquid environments, even under high-pressure conditions of up to 70 bar. Its versatility is made possible by a unique cantilever beam and advanced sensing membrane structure, all neatly packaged within a compact SO16 package.

In electric vehicle heat pump systems, accurate monitoring of refrigerant pressure and temperature is crucial. To prevent damage to expensive system components, liquid media must not enter the compressor. As a result, the refrigerant must remain in a fully superheated gas state upon reaching the evaporator’s outlet. This is achieved by precisely monitoring both pressure and temperature at the same point between the evaporator and compressor, allowing the system to accurately calculate and adjust superheat using a smart expansion valve.

Leveraging Triphibian™ technology and featuring digital SENT output, the MLX90834 provides precise pressure and temperature data. It supports external NTC thermistors and is factory-calibrated to ensure measurement accuracy within ±1°C over a wide temperature range. The precise pressure data can be used to derive the equivalent temperature when the medium is in a saturated state, while the NTC sensor provides the actual fluid temperature.

The MLX90834 is crucial for heat pump manufacturers, especially for smart expansion valves. By integrating this digital sensor chip into components, manufacturers can create intelligent valves with edge computing capabilities. Leveraging Melexis’ sensing and driving expertise, their motor driver chips efficiently process data from the MLX90834. This integrated solution enables direct system control within components, boosting product value. These smart expansion valves offer enhanced pressure and temperature accuracy, minimizing superheat and improving overall system efficiency.

Internally, the MLX90834 integrates sensor signal processing circuitry, digital hardware, a voltage regulator, and digital output drivers. The piezoresistive elements embedded in the sensing membrane form a Wheatstone bridge that detects pressure signals. These signals are amplified and converted into digital form, then temperature-compensated through 16-bit DSP and output via SENT digital mode.

The sensor chip also incorporates advanced voltage protection mechanisms, safeguarding against overvoltage (above +40V) and reverse voltage (below -40V), making it suitable for automotive and truck applications. Additionally, the MLX90834 complies with ISO 26262 as a SEooC (Safety Element out of Context), supporting ASIL C system integration, aligning with the latest EV safety standards.

According to Laurent Otte, Product Line Director at Melexis, "The MLX90834 represents a major breakthrough in our Triphibian™ technology. Not only is it a versatile and efficient pressure sensor, but it also excels in heat pump applications. Our engineering team has succeeded in developing a sensor chip that offers remarkable flexibility, programmability, and intelligence, meeting and surpassing the growing demands of our customers."