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:
Dec. 22, 2009
Filed:
Mar. 14, 2007
Jen-chung Chang, Taoyuan County, TW;
Chia-jung Hsu, Hsinchu, TW;
Shey-shi LU, Taipei, TW;
Yu-che Yang, Taipei, TW;
Tsung-chien Wu, Hualien County, TW;
Tzu-chao Lin, Kaohsiung, TW;
Jen-Chung Chang, Taoyuan County, TW;
Chia-Jung Hsu, Hsinchu, TW;
Shey-Shi Lu, Taipei, TW;
Yu-Che Yang, Taipei, TW;
Tsung-Chien Wu, Hualien County, TW;
Tzu-Chao Lin, Kaohsiung, TW;
United Microelectronics Corp., Hsinchu, TW;
National Taiwan University, Taipei, TW;
Abstract
In a phase locked loop (PLL), phase shifters shift a phase of an input signal. Based on the phases of the input signal, the shifted signals, and a frequency division output signal, phase frequency detectors (PFDs) generate phase difference signals. In response to the phase difference signals, charge pumps (CPs) control output voltages thereof. Based on the output voltages of the CPs, a voltage controlled oscillator (VCO) outputs an output signal. A frequency divider divides the frequency of the output signal from the VCO to generate the frequency division output signal. A circulator outputs the frequency division output signal to one of the PFDs at a proper timing. A modulator reduces quantization errors of the frequency divider.