1. An LED driver, comprisingat least two sub-LED drivers connected in series between two terminals of an AC power source, wherein the at least two sub-LED drivers have a same configuration, each sub-LED driver comprising:
a switch circuit, having a first reference ground interface connected to a first reference ground,
an inductor, having a first terminal connected to the first reference ground; and
a first capacitor, having a first terminal connected to a second terminal of the inductor and a second terminal connected to a second reference ground, and a load comprising at least one LED to be driven connected between the first terminal and the second terminal of the first capacitor;
wherein an inductance value of the inductor in each sub-LED driver causes the sub-LED driver to operate in an open loop mode.