Melexis MLX90834 MEMS Absolute Pressure Sensors
Melexis MLX90834 MEMS Absolute Pressure Sensors are miniaturized MEMS pressure sensors based on Triphibian™ technology. The Melexis MLX90834 sensors robustly handle absolute measurement of gas and liquid media from 2 to 70 bar. The devices feature factory calibration and a SENT output. These sensor ICs provide accurate measurements considerably above 5 bar, but also while in contact with liquid. This innovative combination of high-pressure sensing, while compatible with gas and liquid, is achieved by the unique construction of the MLX90834.
The sensing mechanism contains a suspended cantilever inside an SO16 package with the diaphragm at its tip. This sensor design feature provides pressure spike immunity up to 2000 bar/msec and static burst level up to 210 bar. The available calibrated ranges are tailored to fulfill the demands of a distinct EV thermal management system, including low-/high-pressure refrigeration loops. The MLX90834s design is inherently more robust than rear-side exposed solutions, which still experience a pressure differential between the glass pedestal side and the wire bonding side. The pressure equalization principle is also valid for frozen media, allowing the MLX90834 to survive in such conditions.
The Melexis MLX90834 includes a sensor readout circuit, digital hardware, and voltage regulators and delivers a digital output using the SENT protocol. Piezo-resistive elements implanted into the membrane create a Wheatstone bridge to generate an output signal. This signal is amplified and converted into a digital format, allowing the 16-bit Digital Signal Processing (DSP) to apply compensation. An NTC can be connected for a fast, highly accurate temperature reading of the medium.
The sensors are equipped with advanced protective mechanisms against both overvoltage (above +40V) and reverse voltage (below -40V), making them usable for truck applications. The MLX90830 has been developed as a Safety Element out of Context (SEooC) per ISO 26262, enabling up to ASIL B system integration and ensuring the sensor ICs meet emerging EV safety demands.
Features
- Triphibian technology
- ±0.5% full-scale accuracy over the life
- Digital SENT output
- Option to output linear temperature measured by external NTC thermistor
- Flexible NTC input supports a wide range of different NTC characteristics without calibration
- System in a package
- MEMS
- Analog frontend circuitry
- 16-bit microcontroller
- Voltage regulators
- Digital back-end SENT driver
- Wide automotive temperature range (-40°C to +150°C)
- Qualified according to AEC-Q100 and AEC-Q103-002
- Configurable diagnostic features like internal broken connection, over-voltage, under-voltage, etc.
- Factory-calibrated and fully programmable through the connector with the PTC04 programming tool for customized calibration curves
- Extended over (+40V) and reverse (-40V) voltage capabilities (supply and output)
- Harsh media and liquid media compliant
- ASIL compliant, developed as an ASIL B SEooC as per ISO 26262
- RoHS compliant SOIC16 WB (XG) package
Applications
- Thermal management of electric vehicles
- Standalone sensors
- Embedded sensors in expansion valves
- Embedded sensors in e-compressors
- Embedded sensors in pumps
- Absolute pressures from 2bar to 70bar with gas and/or liquid media
- HVAC-R systems
- Transmission oil monitoring
- Engine oil monitoring
Functional Block Diagram
Basic Application Schematic
Related Development Tools
Melexis PTC-04 Programmer for Melexis PTC Devices
Designed for efficient and precise calibration of the Melexis families of programmable ICs.
Related Products
Melexis MLX9083x Triphibian™ Pressure Sensor ICs
Miniaturized MEMS pressure sensors that robustly measure gas and liquid media from 2 to 70 bar.