The present disclosure discloses a multi-mode dimming circuit configurable to operate in a first dimming mode, a second dimming mode and a third dimming mode. The present disclosure also discloses separate dimming circuits for respectively realize the three dimming modes. In one embodiment the multi-mode dimming circuit may comprise a first input terminal, a second input terminal, a third input terminal, an output terminal, a resistive device, an oscillation circuit and a pulse width modulation (PWM) circuit. Users may flexibly configure the multi-mode dimming circuit to operate in one of the three different dimming modes by varying the external devices and/or signals coupled to each of the first, second and third input terminals.