PLL WITH ACROSS-STAGE CONTROLLED DCO

摘要

In some embodiments, a PLL comprises an across-stage DCO controller and a DCO. The across-stage DCO controller comprises a first detector and a second tuning code adjustor. The first detector receives a first tuning code in a current stage in which an output frequency of the DCO is tuned by a first step size and generates a first detect signal which indicates whether the first tuning code exceeds a first range that the DCO can be correspondingly tuned in the current stage. The second tuning code adjustor adjusts a second tuning code from a previous stage in which the output frequency of the DCO is tuned by a second step size in response to the first detect signal. The second step size is larger than the first step size. The DCO generates the output frequency in response to codes comprising the adjusted second tuning code.

主权项

1. A phase lock loop (PLL), comprising:
an across-stage digital controlled oscillator (DCO) controller comprising:
a first detector configured to receive a first tuning code in a current stage in which an output frequency of a DCO is tuned by a first step size and generate a first detect signal which indicates whether the first tuning code exceeds a first range that the DCO can be correspondingly tuned in the current stage; anda second tuning code adjustor configured to adjust a second tuning code from a previous stage from which the output frequency of the DCO is tuned by a second step size in response to the first detect signal, the second step size being larger than the first step size; and the DCO configured to generate the output frequency in response to codes comprising the adjusted second tuning code from the across-stage DCO controller.