US 12,483,253 B2
Coarse-mover with sequential finer tuning step
Tsung-Hsien Tsai, Taoyuan County (TW); Jason Hsu, Hsinchu (TW); and Ruey-Bin Sheen, Taichung (TW)
Assigned to Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed on Jun. 25, 2024, as Appl. No. 18/753,394.
Application 18/753,394 is a continuation of application No. 17/572,690, filed on Jan. 11, 2022, granted, now 12,052,022.
Claims priority of provisional application 63/219,865, filed on Jul. 9, 2021.
Prior Publication US 2024/0348256 A1, Oct. 17, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H03L 7/099 (2006.01); H03L 7/187 (2006.01)
CPC H03L 7/0992 (2013.01) [H03L 7/187 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A phase locked loop, comprising:
a voltage controlled oscillator (VCO) configured to receive a VCO tuning signal and comprising a plurality of fine tuning devices;
an analog overflow and underflow detector configured to determine whether the VCO tuning signal is above or below an analog voltage range;
a fine tuning counter circuit configured to generate a fine tuning signal; and
wherein, when it is determined by the analog overflow and underflow detector that the VCO tuning signal is above the analog voltage range, a first fine tuning device is selected by the fine tuning signal from the plurality of fine tuning devices to increase a frequency of a VCO output signal to a level within a higher first frequency range,
wherein, when it is determined by the analog overflow and underflow detector that the VCO tuning signal is below the analog voltage range, a second fine tuning device is selected by the fine tuning signal from the plurality of fine tuning devices to decrease the frequency of the VCO output signal to a level within a lower first frequency range.