the frequency divider includes a first or prescaling counter which selects between first and second frequency division factors , in response to a first control signal , and then divides an input signal frequency responsive to the first control signal . a second and programmable counter frequency divides the output of the first or prescaling counter by a third frequency - division factor . a third and programmable counter frequency divides the output of the first counter by a fourth frequency - division factor which is smaller than the third frequency - division factor . a switching control circuit then converts the output of the third counter and supplies the converted signal to the first counter , as the first control signal . the digital frequency divider is suitable for use a part of a phase - locked loop frequency synthesizer .