One-mask customizable phase-locked loop
US6770949B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 31, 1998 |
| Grant date | Aug 3, 2004 |
| Priority date | — |
| Expiry date | Aug 31, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/08
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A system and method in accordance with the invention minimizes the redesign burden in tuning and/or customizing PLLs on ICs. Variable resistors are placed in the PLL in places that facilitate tuning. The variable resistors are formed with a set of at least three contacts, where each contact is in electrical communication with a resistive area. A metal layer is used to form leads to the resistive area, where each lead is formed to be in electrical communication with only a selected subset of contacts from the set. In one embodiment, only the uppermost metal layer used in forming the IC is used to form the leads. Because the uppermost metal layer is utilized, the resistor value can be adjusted simply by selecting the subsets of contacts that are to be in electrical communication with the uppermost metal layer. In this manner, only one metal layer needs to be adjusted in tuning and/or customizing a PLL, rather than having to redesign and re-layout all metal layers and vias in the IC.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.