Melexis launches unique relative pressure sensor IC

There are now many types of pressure sensors, so it is also very important to choose a suitable sensor. Melexis, a global microelectronics engineering company, announced the launch of the relative pressure sensor IC MLX90821 designed to measure extremely low pressure in automotive applications. MLX90821 uses the latest MEMS technology and is a system-in-package solution that is tightly integrated with analog signal chain and digital signal processing technology in the same package. It is suitable for measuring fuel vapor pressure as low as 50 mbar and as high as 700 mbar. Therefore, the MLX90821 is suitable for EVAP systems designed for internal combustion engines or hybrid vehicles.

As more and more regions introduce strict regulations prohibiting the emission of fuel vapor into the atmosphere, it is becoming increasingly important for automobile manufacturers to use EVAP (evaporation) systems for fuel pressure vapor detection. The EVAP system captures, stores and processes vapor that can accumulate in the fuel tank and crankcase, preventing it from escaping into the air. Pressure sensor ICs that can measure very low pressures, such as the MLX90821, are a key component of such systems because they are able to detect extremely small leaks that may occur anywhere in the EVAP system.

“The measurement range, reliability, stability and accuracy of the relative pressure sensor MLX90821 are sufficient for EVAP systems for internal combustion and hybrid engines,” comments Laurent Otte, product line manager for pressure sensors at Melexis. “With this factory-calibrated sensor IC that can be custom calibrated for each individual application, Tier 1 manufacturers and module manufacturers can use a standardized single design for both engines. The sensor IC is packaged to be reliable and easy to install Sealed and certified to operate in temperatures ranging from -40°C to +150°C, with full PPAP support."

Fuel vapor pressure measurement in hybrid vehicles is even more complex and requires more capable sensing solutions. In addition, since the EVAP system in ICE (internal combustion engine) and hybrid vehicles may be equipped with multiple pressure sensor ICs, it is important to adopt a flexible and simple design. The MLX90821 is small in size and can be used in almost any size module. It can also achieve a high degree of integration through system-in-package, making it a simple-to-design, "plug and play" solution. DSP provides analog output and SENT output, and can make full use of the fast and slow channels of the SENT interface to add diagnostic messages and customer-defined information. The MLX90821 provides a variety of diagnostics required for automotive applications, including clamp level, break trace diagnostics, and multiple internal fault diagnostics.

The system-in-package solution uses MEMS sensors fabricated through backside etching technology. Therefore, the sensing element has high media compatibility against contaminants when exposed to harsh environments such as fuel vapor or other media. The CMOS portion of the system provides design flexibility, while the entire sensor provides an extremely high level of EMC protection and immunity, making it easy to integrate into ICE and hybrid vehicle EVAP systems.

Each sensor IC is calibrated during the final production step and the pressure transfer curve and clamping levels are stored in internal EEPROM. The measurement results are provided via a proportional analog output or SENT output, which can include temperature measurement. When the application also needs to output the accurate temperature measurement value of the measured medium, you can choose to use an external NTC to output the temperature value after temperature compensation. Further configuration can be performed using software and hardware tools provided and supported by Melexis. The above is the unique relative pressure sensor IC launched by Melexis suitable for ICE and hybrid vehicle EVAP systems. I hope it can provide some help when you choose.