A driver circuit supplies a positive voltage and a negative voltage to a load. The driver circuit includes: a positive power conversion circuit, coupled to the load, and generating the positive voltage according to an input voltage; a negative power conversion circuit, coupled to the positive power conversion circuit and the load, and generating the negative voltage according to the positive voltage; and a headroom adaptive adjustment circuit, coupled to the positive power conversion circuit and the load, and generating an adjustment signal according to one or more of a load current flowing through the load, the positive voltage Vp and the negative voltage Vn. The adjustment signal is sent to the positive power conversion circuit to adjust a regulation target of the positive voltage.