WPAT, P.C., Intellectual Property Attorneys
Frequency scaling method, circuit and associated all-digital phase-locked loop
A frequency scaling method is disclosed. The method is used for changing an output frequency of an all-digital phase-locked loop (ADPLL) from a first frequency to a second frequency different from the first frequency. The method includes: stopping a feeding of a first oscillator tuning word (OTW) to a digitally controlled oscillator (DCO) of the ADPLL, wherein the first OTW is generated based on a phase detecting result obtained with respect to the first frequency; feeding a second OTW to the DCO in order to change the output frequency from the first frequency to the second frequency; and performing a zero phase restart (ZPR) operation to produce the phase detecting result according to the second frequency. An associated ADPLL and a frequency scaling circuit are also disclosed.
TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
H H H
H03L H03K H03L
additional inventional inventional
Tsung-Hsien Chih-Hsien
Tsai Chang