HIGH OUTPUT IMPEDANCE CHARGE PUMP FOR PLL/DLL

摘要

A charge pump for use in a Phase Locked Loop/Delay Locked Loop, comprising a pull-up circuit, a pull-down circuit, and an operational amplifier. The charge pump is designed to minimize the static phase error associated with the operation of the pull-up and pull down circuits. The use of the operational amplifier also mitigates the effects of low power supply voltage.