A circuit protective system. The system has: (i) an input for sensing an operational voltage responsive to a current flowing through a transistor; (ii) circuitry for applying a forced voltage at the input; (iii) voltage-to-current conversion circuitry for outputting a reference current in response to the forced voltage at the input; (iv) circuitry for providing a reference trim current in response to a trim indicator; and (v) comparison circuitry for outputting a limit signal in response to a comparison of the reference current and the reference trim current.