Fully integrated phase-locked loop with resistor-less loop filer
US6157691A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 14, 1998 |
| Grant date | Dec 5, 2000 |
| Priority date | — |
| Expiry date | Apr 14, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L2207/06
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A phase-locked loop includes a phase detector, a charge pump, a resistor-less loop filter and a voltage-controlled oscillator ("VCO"). The phase detector has a reference input, a feedback input, and a charge control output. The charge pump is coupled to the charge control output, and the resistor-less loop filter is coupled to the charge pump. The VCO has a control voltage input coupled to the resistor-less loop filter, a clock output coupled to the feedback input and a plurality of delay elements which are coupled together in series to form a ring oscillator. Each delay element includes a delay element output. A MOSFET gate oxide capacitance is coupled between each delay element output and the charge control output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.