Pressure transducer based on the piezoresistive effect whereby pressure causes an elastic semiconductor structure to change, which in turn changes the values for resistances connected as a Wheatstone bridge circuit (Figure P 8). Two types of piezoresistive pressure sensors are manufactured:
- silicon resistors stuck on precious metal diaphragms and
- resistors attached to the surface of a silicon diaphragm.
A distinction needs to be made here between:
- monolithic sensors with only one resistance bridge;
- sensors with temperature compensation;
- sensors with an output amplifier
Figure P 8: Piezoresistive pressure sensor