A CIRCUIT FOR GENERATING A NEGATIVE VOLTAGE SUPPLY SIGNAL, AND ASSOCIATED POWER SUPPLY DEVICE AND PORTABLE ELECTRONIC APPARATUS

摘要

A circuit for generating a negative voltage supply signal is disclosed. The circuit has a first capacitive element (C2) coupled to receive a switched input signal (413) which switches at least between a first state (S1) with a positive first voltage (n) and a second state (S2) with a second voltage, different from the first voltage. A second capacitive element (C3) is coupled to provide the negative voltage supply signal (Vout-). Control circuitry (D2, D3) is coupled to the first capacitive element and the second capacitive element. The control circuitry is arranged, in the first state of the switched input signal, to enable charging of the first capacitive element by the switched input signal, and, in the second state of the switched input signal, to enable charging of the second capacitive element by the first capacitive element to generate the negative voltage supply signal.