Operational mode changes in a system-on-a-chip (SoC) integrated circuit in a complex device such as a mobile phone cause spikes in current demand which can cause voltage droops that disrupt operation of the SoC. A hybrid parallel power supply connects a switching-mode power supply and a low-dropout voltage regulator in parallel to provide high efficiency and fast response times. Integration of the voltage regulator on the SoC reduces parasitic impedance be between the voltage regulator and the load to aid in reducing voltage droops. The switching-mode power supply and the low-dropout voltage regulator can regulate their outputs to slightly difference voltage levels. This can allow the switching-mode power supply to supply most of the SoC's current demands.