Output ripple voltage control for a capacitive DC/DC converter

摘要

A switching direct current (DC)-to-DC converter includes a charge pump circuit with a flying capacitor (104) and a switching circuit (106). The switching circuit (106) has an ON resistance (R_on) and is configured and arranged to boost an input voltage (V_in) by operating in each of a charging mode (loading) during which charge is provided from the flying capacitor (104) to an output voltage (V_out) and a discharging mode (storing) during which charge is not provided from the flying capacitor (104) to the output voltage (V_out). A determination circuit (102) is configured and arranged to determine a ratio between a discharge rate (308) and a charge rate (310). The discharge rate (308) and the charge rate (310) both correspond to a rate of change for the output voltage of the switching DC-to-DC converter. An ON resistance circuit (102) module is configured and arranged to adjust the ON resistance (R_on) of the charging mode (loading) and to change the determined ratio to a target ratio.