VCO having voltage-to-current converter and PLL using same
US5359298A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 29, 1993 |
| Grant date | Oct 25, 1994 |
| Priority date | — |
| Expiry date | Dec 29, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L2207/04
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The voltage controlled oscillator in a phase-locked loop comprises a voltage-current converter (62) and a current frequency converter (34). The voltage-current converter (62) comprises a voltage differential-current converter (64), a current-current converter (66) and a current adder-subtracter (68). In the voltage differential-current converter (64), only the voltage fluctuation or difference .DELTA.V.sub.CN with respect to one half a power supply voltage V.sub.DD /2, and not the absolute value of a control voltage V.sub.CN, undergoes current conversion as a control current I.sub.CN. Therefore, the center frequency of the oscillation frequency is not a factor of control voltage V.sub.CN and is controlled only by an offset voltage V.sub.B2. Accordingly, the center frequency can be independently set by changing offset voltage VB.sub.2. This is particularly significant in zone bit recording, which requires a wide frequency band.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.