Patent ID: 8022740

Claim:
A phase-locked loop circuit comprising: a phase frequency detector operating at a low voltage and providing low-voltage sourcing control signals and low-voltage sinking control signals at the low voltage; and a charge pump operating at a high voltage and including a sourcing control circuit coupled to the low-voltage sourcing control signals and selectively causing the charge pump to source the sourcing current to an output of the charge pump based on the low-voltage sourcing control signals, wherein the low-voltage sourcing control signals have not been level shifted in voltage level to a voltage higher than the low voltage to selectively cause the charge pump to source the sourcing current; and a sinking control circuit receiving the low-voltage sinking control signals and selectively causing the charge pump to sink the sinking current from the output of the charge pump based on the low-voltage sinking control signals, wherein the low-voltage sinking control signals have not been level shifted in voltage level to a voltage higher than the low voltage to selectively cause the charge pump to sink the sinking current.