In accordance with some embodiments of the present invention, a method of determining a Q-factor in a transmit circuit with a resonant circuit includes setting a system voltage; performing a coarse scan to determine a course resonant frequency; performing a fine scan based on the course scan to determine a resonant frequency; performing a final measurement at the resonant frequency to determine an average system voltage and an average peak voltage of the resonant circuit; calculating a Q parameter from the average system voltage and the average peak voltage; and calculating the Q-factor from the Q parameter.