Calibration of a phase locked loop and applications thereof within a radio
frequency integrated circuit begins by determining an intersection of an
up current and down current produced by a charge pump within the phase
locked loop. The RFIC then determines a reference voltage corresponding
to the intersection, which varies from an ideal voltage of V.sub.DD/2
based on process variations. The RFIC then offsets a control voltage to
the voltage control oscillator (VCO) of the phase locked loop based on
the reference voltage. Accordingly, by determining the offset of the
actual intersection from the ideal intersection, the control voltage to
the VCO may be adjusted thereby calibrating the phase locked loop for
more linear performance.