A system for sensing current that includes a processor and a current sensor coupled to the processor. The current sensor includes a sensor threshold value. The system also includes a current generator coupled to the current sensor. The current generator is operable to generate a test current signal defined by a time-varying linear function. The current sensor is operable to be coupled to an external current source and to output a sensor output signal based on a detected current to the processor. The processor is operable to determine a magnitude of the sensor threshold value based on the sensor output signal.