High-speed resistor-based charge pump for active loop filter-based phase-locked loops

Abstract

Techniques are described for increasing the speed of a resistor-based charge pump for an active loop filter-based phase-locked loop (PLL). The techniques may include placing a low-resistance discharge path between respective nodes of a current source and sink in a charge pump, and selectively activating the low-resistance discharge path when the charge pump is turned off. The low-resistance discharge path may have a resistance that is lower than the resistance of other current paths between the respective nodes in the charge pump (e.g., current paths formed by the resistors included in the current source and sink of the charge pump), thereby reducing the amount of time needed to reset the charge on the respective nodes when the charge pump is turned off. In this way, the speed of a resistor-based charge pump may be increased, thereby allowing the overall speed of an active filter-based PLL to be increased.

Dependencies are inferred from the claim text.