Patent ID: 7388440

Claim:
A circuit, comprising: a phase loop circuit including a voltage controlled oscillator having an input; and a lock aid circuit coupled with the input of the voltage controlled oscillator, wherein the lock aid circuit includes: a first amplifier configured as a Schmitt trigger having an output and an input; a first switch having an output and an input and a control; a second amplifier having an input coupled with the output of the first amplifier, the second amplifier having an output coupled with the control of the switch; the input of the switch being coupled with the input of the voltage controlled oscillator, and the output of the switch being coupled with ground; and a second switch having an output and an input and a control, the input of the second switch is coupled with the output of the first amplifier, the output of the second switch is coupled with ground, and the control of the second switch is coupled with a voltage signal to disable the lock aid circuit.