PLL circuit and wireless mobile station with that PLL circuit
US6912380B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Mar 29, 2001 |
| Grant date | Jun 28, 2005 |
| Priority date | — |
| Expiry date | Sep 29, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L2207/12
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In a PLL circuit, and a wireless mobile station with that PLL circuit, an LPF charging constant current source, a discharging constant current source and a high-speed charging constant current source are connected to an output terminal of a phase comparator with current mode output. When a convergence frequency of the PLL circuit is low, an input voltage of a VCO is increased from OV so as to be converged by using the constant current source. However, when the convergence frequency of the PLL circuit is high, the input voltage of the PLL circuit is temporarily increased to the maximum voltage by using the constant current source. Thereafter, the input voltage is gradually dropped from the maximum voltage so as to be converged by using the constant current source.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.