FAST ACQUISITION PHASE LOCKED LOOP USING A CURRENT DAC

摘要

In a phase locked loop in which a phase detector compares an input signal to a reference signal and provides a difference signal to a charge pump or to a transconductance amplifier, a digital to analog converter is provided for connecting the output of the charge pump or transconductance amplifier to a voltage controlled oscillator whereby loop bandwidth can be increased from an operating value to an acquisition value for loop phase acquisition by changing the input to the DAC, thereby changing the amplification of the DAC.