Abstract: A dual signal path provides enhanced noise cancellation for phase locked loop applications. According to various aspects of the invention, dual charge pumps are used to split the phase locked loop signal into dual signal paths, wherein each path carries an information signal with an injected noise component. The dual signal paths are arranged to maintain the magnitude and phase characteristics of the injected noise component. Filter blocks process the signals, retaining the injected noise component. The filtered signals are coupled to the input of an adder circuit where the filtered signals are subtracted. Because each filtered signal contains the injected noise component, the subtraction operation effectively cancels the injected noise component from the filtered signals.

Abstract: A dual signal path provides enhanced noise cancellation for phase locked loop applications. According to various aspects of the invention, dual charge pumps are used to split the phase locked loop signal into dual signal paths, wherein each path carries an information signal with an injected noise component. The dual signal paths are arranged to maintain the magnitude and phase characteristics of the injected noise component. Filter blocks process the signals, retaining the injected noise component. The filtered signals are coupled to the input of an adder circuit where the filtered signals are subtracted. Because each filtered signal contains the injected noise component, the subtraction operation effectively cancels the injected noise component from the filtered signals.