Silicon Multi-Stage Current-Mode Piezoresistive Pressure Sensor with analog temperature compensation

This work presents a technique for temperature compensation of Silicon Piezoresistive Pressure Sensors (PPSs) based on a Proportional to Absolute Temperature (PTAT) Bias-Current circuit (I_PTAT). This technique is applied on the Multi-Stage Current-Mode Piezoresistive Pressure Sensor based on a 3-Terminal Pressure Sensor (3-TPS) that recently has been being studied as an alternative to the conventional Wheatstone Bridge and Transversal PPSs. The experimental maximum differential sensitivity of the sensor output current relative change, for 500μA constant bias current, amounts to 0.64%/psi @20°C. The sensor output current sensitivity temperature dependence, without compensation, amounts to 0.06μA/°C over a range from 20°C to 80°C. After compensation, the experimental results show a maximum deviation of 1.5% within the full scale output span. This efficient compensation was achieved using a PTAT bias current whose Temperature Coefficient (TC) amounts to 0.06μA/°C.