The present disclosure provides a driving circuit, configured to couple to a light emitting diode (LED) and a power supply circuit. The driving circuit includes a comparator, a serial input interface, and an integrating unit. The comparator is configured to couple to the LED and determine whether a cathode voltage of the LED is lower than a threshold value and generate a monitoring data. The serial input interface is configured to receive a serial input data from a previous driving circuit. The integrating unit is coupled to the comparator and the serial input interface and configured to integrate the monitoring data and the serial input data to generate an output data. The output data is transmitted to a following driving circuit or feedbacked to the power supply circuit in order to modulate a power voltage that the power circuit provides to the LED.