if u03b6 0 is given by the first solution to where u03c4 u2212 refers to the time to crossover with a positive negative phase step swapping the polarity of the phase step is equivalent to swapping the polarity of the offset when u03b8 offset lt lt u03b8 step and the first solution to 4 is considered first time to crossover it can be shown that thus the average time to crossover measurement with opposite polarity pulses and with u03b6 0 is only a function of u03c9 n for a stable pll u03b6 is typically set to be greater than 1 if the u03b6 is close to zero then the pll is on the edge of instability this is not a desirable state to be in in a practical application however u03b6 can be temporarily set to zero by turning off the proportional path provided that the proportional path is turned off for less than the natural period of the pll 2 u03c0 u03c9 n then the pll will not oscillate the following algorithm can be used to measure the values of u03c9 n u03b6 and the pll 39 s phase offset u03c6 offset step 1 the pll is allowed to lock with the integral path and proportional path gains set to a default value step 2 a phase step is introduced into the pll by changing.