Complementary metal-oxide semiconductor high-frequency ring oscillator
US6097256A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 11, 1999 |
| Grant date | Aug 1, 2000 |
| Priority date | — |
| Expiry date | Mar 11, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K3/354
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A CMOS (complementary metal-oxide semiconductor) high-frequency ring oscillator is provided for generating an output frequency in response to a control voltage in a wide bandwidth. The ring oscillator is of the type including a plurality of cascaded delay circuits, such as CMOS CSL (common-sense logic) inverters. The ring oscillator is characterized by the additional incorporation of each of the CMOS CSL inverters with either a positive-feedback gate structure or a positive-feedback drain structure so as to improve the output-to-output characteristics of the ring oscillator. More specifically, the ring oscillator is still operable to output an oscillating signal even though the control voltage is reduced to below a certain level, at which point the gain is still larger than 1. The ring oscillator is therefore more advantageous than the prior art both in gain and output-to-output characteristics and is operable over a wide variety of output frequencies, particularly in the low-frequency regions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.