Clock, frequency reference, and other reference signal generator with frequency stability over temperature variation
US8134414B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 23, 2010 |
| Grant date | Mar 13, 2012 |
| Priority date | — |
| Expiry date | May 6, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03B5/1293
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Exemplary embodiments provide a reference signal generator having a reference or center frequency within a predetermined variance over variations in temperature within a specified range. An exemplary apparatus comprises a reference resonator to generate a first reference signal having a resonant frequency, with the reference resonator having a first temperature dependence; and a plurality of switchable circuits, with at least one switchable circuit providing a second temperature dependence opposing the first temperature dependence to maintain the resonant frequency within a predetermined variance over a temperature variation. A wide variety of switchable circuits are disclosed, including a transistor having an on resistance value greater than a nominal resistance, a resistor coupled to a transistor or other switch, and circuit comprising a first reactance coupled to a first switch, with a second reactance coupled to a resistance and a second switch coupled in series to the second reactance or to the resistance. Various coatings may also be applied to an integrated circuit embodiment, such as a silicone coating on a first surface and a metal layer on a second surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.