Programmable spread spectrum clock generation based on successive phase selection technique

A wideband frequency modulator capable of modulating the input frequency within a range of 0.5% to 5% with a programmable step of 0.5% is presented. The block has been built in 65nm technology with a low power consumption of 1mW. The proposed topology uses a period locking delay locked loop, phase interpolator and a digital controller to modulate the input frequency and gives the flexibility of controlling the shape of the modulating signal.