A dimming controller is capable of receiving a dimming signal to dim light-emitting device no matter the dimming signal is of DC or of PWM. A type identifier identifies whether the dimming signal received from an input node is of DC or of PWM. A multiplexer with an output is controlled by the type identifier and configured to provide at least a DC signal path and a PWM signal path both coupled between the input node and the output. The type identifier makes the multiplexer enable the DC signal path and interrupt the PWM signal path if the dimming signal is identified as of DC, and makes the multiplexer enable the PWM signal path and interrupt the DC signal path if the dimming signal is identified as of PWM.