There is provided a lamp driver including: a power supplying part switching an input power, supplying a driving power to at least one lamp, and controlling brightness of the at least one lamp according to a dimming signal; a signal supplying part supplying a first comparison result signal obtained by comparing a current sensing signal sensing a current flowing through the at least one lamp with a reference signal having a current level set beforehand when the dimming signal is a logic high signal, and supplying a second comparison result signal having a voltage level set beforehand when the dimming signal is a logic low signal; and a controlling part controlling the switching of the power supplying part according to a signal being supplied by the signal supplying part.