Light source driving systems and devices

A light source driving device comprising:

• a sensing terminal configured to sense a power supply status of a first set of LEDs driven by said light source driving device, wherein said power supply status of said first set of LEDs comprises a power-sufficient state and a power-increasable state;
• a serial communication terminal configured to communicate serially with a first adjacent driving device;
• a feedback input terminal configured to receive a feedback input voltage from said first adjacent driving device, wherein said feedback input voltage indicates a power supply status of a second set of LEDs driven by said first adjacent driving device;
• a feedback output terminal configured to provide a feedback output signal to adjust a supply voltage of said first set of LEDs and said second set of LEDs;
• and
• a control circuit, coupled to said feedback input terminal and said feedback output terminal, and configured to generate an internal voltage according to said power supply status of said first set of LEDs, select a feedback voltage from said internal voltage and said feedback input voltage, and to generate said feedback output signal according to said feedback voltage, wherein said control circuit is also configured to operate in a mode of a voltage feedback mode and a current feedback mode based on an application condition of said light source driving device, wherein in said voltage feedback mode, said feedback output signal comprises a feedback output voltage controlled by said feedback voltage, and wherein in said current feedback mode, said feedback output signal comprises a feedback output current controlled by said feedback voltage.