The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 06, 2016
Filed:
May. 21, 2015
Stmicroelectronics International N.v., Amsterdamn, NL;
Abhirup Lahiri, Delhi, IN;
STMicroelectronics International N.V., Amsterdam, NL;
Abstract
A phase-locked-loop includes a phase-frequency-detector (PFD) comparing phases of an input signal and feedback signal, and generating therefrom control signals. An attenuation circuit in series with the PFD includes a filter between a voltage-controlled-oscillator (VCO) control node and ground. A buffer is coupled to the VCO control node. An impedance network is coupled to the VCO control node and has an impedance element coupled to a first current source so voltage at the VCO control node increases when control signals indicate the phase of the input signal leads the feedback signal, and coupled to a second current source so voltage at the VCO control node decreases when control signals indicate a lagging phase. A VCO is coupled to the VCO control node to generate an output signal, with the phase of the output signal matching the input signal. The feedback signal is based upon the output signal.