A circuit for setting a threshold level for extracting data from a signal stream includes a terminal couplable to the signal stream. A peak detector is coupled to the terminal. A valley detector is coupled to the terminal. A comparator is coupled to outputs of the peak detector and the valley detector for generating a threshold voltage for extracting data or commands from the signal stream. A method of extracting data from a signal stream including: peak detecting the signal stream to generate a first signal; valley detecting the signal stream to generate a second signal; combining the first and second signals to generate a threshold signal; and extracting data from the signal stream utilizing the threshold level signal.