The MLX90821 sensor IC is designed for measuring very low pressures in automotive applications. Using the latest MEMS technology closely integrated with an analog signal chain and digital signal processing, the device is a system-in-package IC solution for the reliable measurement of fuel vapor pressure as low as 50 mbar and up to 700 mbar.
As vapor builds up inside fuel tanks and crank cases, the EVAP systems are designed to capture, store and responsibly dispose of the vapor, preventing it from escaping into the air. Pressure sensors that can operate at very low pressures, like the MLX90821, are a crucial part of these systems, as they are able to detect even the smallest leaks that can potentially appear at any point in the EVAP system.
The MLX90821 has the range, reliability, stability and accuracy to cover EVAP systems for both internal combustion and hybrid engines, giving tier 1 and module manufacturers the ability to standardize on a single design for both types of engine, using a sensor IC that is factory calibrated but can also be customized for each individual application. Its packaging is certified to operate between -40 ℃ and +150 ℃.
Fuel vapor pressure measurement is even more complex in hybrid vehicles, creating demand for more capable sensing solutions. Also, as EVAP systems in both ICE (internal combustion engine) and hybrid vehicles may feature several pressure sensor ICs, design flexibility and simplicity are critical. While being small enough to be used in any size module, the high level of integration provided through the system-in-package approach makes designing with the MLX90821 extremely simple, providing what is essentially a ‘plug & play’ approach. While both analog and SENT outputs are provided, the DSP offers the ability to make full use of the SENT interface’s fast channel and slow channel, add diagnostic messaging and apply custom calibration. The MLX90821 offers multiple automotive diagnostic features, including clamping levels, broken track diagnostics and multiple internal fault diagnostics.