Piezoresistive pressure sensors are usually designed for operating temperatures up to about 130°C. The CiS Research Institute is able to develop and manufacture piezoresistive pressure sensor chips for operating temperatures up to 300°C by adapting chip design and semiconductor technology.
The raw signals of the sensor element are processed by an ASIC. The calibration data for the temperature compensation of the output signal are also stored here. At present, hardly any commercial ASICs are available for applications in the extended operating temperature range. Until now, the ASIC was spatially separated from the measuring location of the pressure sensor chip. This led to a reduction in measurement accuracy, an increase in installation space and an increase in manufacturing costs.
To solve this problem, the AniTHA project designed and implemented analog temperature compensation integrated on the sensor chip for operating temperatures up to about 300°C, which offers the following advantages:
- No high-temperature ASICs are required for temperature compensation.
- Systematic temperature errors are avoided, which arise because the (conventional) ASIC is spatially offset from the location of the sensor and thus both locations have different temperatures (location of pressure measurement and location of temperature measurement). At the same time, the dynamics of the system are improved during temperature changes.
- The required installation space of the measuring system as well as its manufacturing costs can be reduced.
The solution can also be applied to classic piezoresistive Si pressure sensors in the temperature range up to 130°C as analog precompensation. The advantage here is that fewer temperature support points are required for the calibrations, or depending on the desired accuracy, the calibration can even be omitted altogether.
The research and development work in the “Analog Integrated Temperature Compensation for High-Temperature Applications” (AniTHA) project was funded by the German Federal Ministry for Economic Affairs and Energy.
Funding code: 49MF180042