Patent ID: 7312645

Claim:
A data triggered phase locked loop (PLL) comprises: phase detector operably coupled to determine a phase difference between transitions of a data signal and a feedback signal; charge pump operably coupled to convert the phase difference into a charge pump current; loop filter operably coupled to convert the charge pump current into a control voltage; voltage controlled oscillator operably coupled to convert the control voltage into a recovered clock, wherein feedback signal is derived from the recovered clock; and edge detection module operably coupled to detect missing transitions of the data signal and to alter at least one of the phase difference and charge pump current based on the missing transitions such that bandwidth of the data triggered PLL remains substantially constant for varying data signal transition densities, the missing transitions being detected by: comparing transitions of the recovered clock with transitions of the data signal; when a transition occurs in the recovered clock and a substantially contemporaneously transition does not occur in the data signal, indicating a missing transition of the data signal; incrementing a missing transition count of the data signal based on the indication of the missing transition until a transition of the data signal occurs substantially contemporaneously with another transition of the recovered clock to produce an accumulated missing transition count; and at each transition of the data signal, establishing a phase error scaling factor based on the accumulated missing transition count and a phase error-to-missing transition relationship by: establishing a normalized phase error in accordance with the accumulated missing transition count as the phase error-to-missing transition relationship, wherein the normalized phase error corresponds to (n+2)/2 for [0 . . . n], wherein n corresponds to a numerical value of the accumulated missing transition count; and summing the normalized phase error to produce the phase error scaling factor.