In one embodiment, an apparatus includes a circuit coupled to a line, where the circuit may power a device, and where the power is transmitted to the device over the line as a pulse-width modulated signal. The circuit may set a duty cycle of the pulse-width modulated signal in order to transmit a determined power level to the device. The apparatus may vary a frequency of the pulse-width modulated signal to transmit data to the device while the duty cycle of the pulse-width modulated signal is fixed in order to continue to transmit the determined power level to the device. A variation in the frequency of the pulse-width modulated signal may be detectable by the device and represents at least a portion of the data.