Patent ID: 7439812

Claim:
A phase locked loop circuit, comprising: a voltage controlled oscillator, including a control input and a frequency output; a dividing circuit including a signal input coupled to the frequency output of the voltage controlled oscillator, a range input, and a signal output; a phase detector including a reference input, a feedback input coupled to the signal output of the dividing circuit, and an output; a loop filter coupled to the output of the phase detector and the control input of the voltage controlled oscillator; and a rangefinder circuit including a reference input coupled to the reference input of the phase detector, a range output coupled to the range input of the dividing circuit, a pulse generator including an input and an output, a counter including a clock input coupled to the reference input of the rangefinder circuit, a reset input coupled to the output of the pulse generator, and an output, register including a count input coupled to the output of the counter, an enable input coupled to the output of the pulse generator, and an output, and a state machine including a count input coupled to the output of the register, and a state output coupled to the range output of the rangefinder circuit.