STRESS SENSOR AND METHODS OF OPERATING SAME

A stress sensor is provided, including a substrate and a bridge circuit disposed thereon. The bridge circuit is coupled between an output node and a ground node. The bridge circuit includes a first and second branch, the first branch having a first resistor coupled to a tunable resistor at a first intermediate node. The second branch has a second resistor coupled to a variable reference resistor of value Rref at a second intermediate node, wherein the variable reference resistor is configured to sweep through a plurality of discrete values Rref. The bridge circuit also includes an amplifier having a positive input terminal coupled to the first intermediate node and a negative input terminal coupled to the second intermediate node. The amplifier is configured to generate a digital voltage output at the output node as a function of the mechanical stress applied to the substrate and of the value Rref.