The invention relates to electric lighting facilities powered from an external electrical network. The light-emitting diode lamp comprises a step-down voltage converter (1) made up of a chain of capacitors (2, 3, 4) connected in series, one of which is a power take-off capacitor (3) and is connected to at least one pair (5) of inverse-parallel connected light-emitting diodes (6, 7). The invention makes it possible to achieve extremely low electrical energy consumption for lighting, ensure optimum performance, and use the circuit for the additional function of supplying power to external users of, for example, mobile telephones.