Aspects of the present disclosure include a dimming device comprising a dimming signal interface module which includes an optical coupling module and an analog-digital converter module having its input terminal connected to the input terminal of the dimming signal interface module and its output terminal selectively connected to the optical coupling module. The dimming signal interface module may receive digital signals and analog signals. When the analog signals are received by the input terminal of the dimming signal interface module, the analog-digital converter module may convert the analog signals to square-wave signals and output the square-wave signals to the optical coupling module. When digital signals are received by the input terminal of the dimming signal interface module, the output terminal of the analog-digital converter module may be disconnected from the optical coupling module. The dimming device may be able to receive digital and analog control signals to be used for dimming.