A high-output ratio DC DC converter supplies at least two regulated output voltages, a positive voltage Vs+ and a negative voltage Vs- from a direct current voltage Vin applied at the input, by means of two voltage boost structures with pairs of switches SBp1, SHp1, and groups of input capacitors Gin1 and output capacitors Gout1, controlled by an inductive stage with inductance Lin and controlled switch M, a level translator circuit with capacitor Ct and direct diode Dt being provided between the said inductive stage and the structure supplying the negative output voltage.