A negative voltage circuit includes a dual charging circuit, a pumping capacitor circuit, a dual discharging circuit, an output switch circuit, and a load capacitor circuit. The dual charging circuit is configured to operate in a start-up or normal operating mode during a charging mode, and supply a first current in the start-up mode higher than a second current in the normal operating mode. The pumping capacitor circuit is configured to charge based on a charging current from the dual charging circuit. The dual discharging circuit is configured to operate in the start-up mode or the normal operating mode during a discharging mode, and discharge the pumping capacitor to allow a third current in the start-up mode to flow between the pumping capacitor and the terminal of the second operating voltage. The third current in the start-up mode is higher than a fourth current in the normal operating mode.