The invention provides a phase frequency detector and charge pump circuit for a phase locked loop. The prior art has the defects of poor linearity and noise performance, so when a first series circuit is connected with the output end of a current pump, an upstream biasing circuit is used as a biasing circuit of an upstream current source; and when a second series circuit is connected with the output end of the current pump, a downstream biasing current source is used as a biasing circuit of a downstream current source. By adding the two fixed biasing currents and selecting proper biasing current according to the output voltage of the charge pump, phase difference of two input ends of the phase frequency detector deviates from zero after the PLL loop is locked, so that the aim of enhancing the linearity of the phase frequency detector and the charge pump and improving the noise performance of a fractional-N phase locked loop can be achieved.