Abstract: A sensor interface for a resistive sensor has an analog front end comprising. The analog front end has an analog input/output (I/O) sensor port to be coupled to the resistive sensor. An integration stage is coupled to the analog I/O sensor port to oscillate at an oscillation frequency proportional to a sensor resistance of the resistive sensor. The integration stage has a variable integrator capacitance to vary the oscillation frequency. A gain stage is coupled to the integration stage and has a variable gain to vary the oscillation frequency of the integration stage. The sensor interface also has a smart digital controller (SDC) coupled to the analog front end to compute the sensor resistance of the resistive sensor based on the oscillation frequency. In addition, the SDC automatically detects unstable oscillation in the integration stage and causes the variable gain and the variable integrator capacitance to change.

Abstract: A sensor interface for a resistive sensor has an analog front end comprising. The analog front end has an analog input/output (I/O) sensor port to be coupled to the resistive sensor. An integration stage is coupled to the analog I/O sensor port to oscillate at an oscillation frequency proportional to a sensor resistance of the resistive sensor. The integration stage has a variable integrator capacitance to vary the oscillation frequency. A gain stage is coupled to the integration stage and has a variable gain to vary the oscillation frequency of the integration stage. The sensor interface also has a smart digital controller (SDC) coupled to the analog front end to compute the sensor resistance of the resistive sensor based on the oscillation frequency. In addition, the SDC automatically detects unstable oscillation in the integration stage and causes the variable gain and the variable integrator capacitance to change.