A method of converting a positive voltage to a negative voltage includes applying an input signal having intermittent high- (e.g., positive-) and low (e.g., zero or ground) levels to a capacitor network having two or more capacitors; configuring the network into a serial configuration, in which the capacitors are connected to each other in series; charging the capacitors connected in series with the input signal during a pre-charge period, during which the input signal level is high; subsequently, during a pump period, during which the input signal level is low, configuring the network into a parallel configuration, in which the capacitors are connected to each other in parallel; and discharging the capacitors connected in parallel to an output. A negative charge pump includes a network of two or more capacitors, and switches and adapted to switch the capacitor network between a serial configuration, in which the capacitors are connected to each other in series, and a parallel configuration, in which the capacitors are connected to each other in parallel. The negative charge pump has an input adapted to receive an input signal having intermittent high- and low levels, and an output. The switches are adapted to switch the capacitor network into the serial configuration when the input signal is high and switch the switch the capacitor network into the parallel configuration when the input signal is low (e.g., zero or ground level).