Abstract: A frequency divider circuit (11) has an input port for an input signal (Fo) to be divided, an output port for a divided signal (FDIV), and means (12-19) for providing a variable division-ratio control signal (N+C) and a residual quantization error signal (R), applying the variable division ratio control signal (N+C) to a control port of the frequency divider, and using the residual quantization error signal (R) to cancel phase error in the divided signal. Both the variable division ratio control signal (N+C) and the residual quantization error signal (R) are dithered.

Abstract: The present invention provides a method and apparatus which provides a signal with an output frequency higher than an input frequency. A phase generator generates multiple phase signals from the input signal with each phase signal having the same frequency as the input signal but being out of phase with the input signal by multiples of a set time interval. These phase signals are transmitted to a multiplexer. The multiplexer output is determined by a select word generated by an accumulator from a stored value. The accumulator is clocked by the multiplexer output and the accumulator adds a control word with a set value to the stored value in the accumulator. This addition is accomplished at every cycle of the multiplexer output. By judiciously choosing control word and the time interval between phases, frequencies higher that the input frequency can be generated at the multiplexer output.

Abstract: A frequency divider circuit (11) has an input port for an input signal (F0) to be divided, an output port for a divided signal (FDIV), and means (12-19) for providing a variable division-ratio control signal (N+C) and a residual quantization error signal (R), applying the variable division ratio control signal (N+C) to a control port of the frequency divider, and using the residual quantization error signal (R) to cancel phase error in the divided signal. Both the variable division ratio control signal (N+C) and the residual quantization error signal (R) are dithered.