Voltage controlled oscillation circuit having oscillation frequency variable control units inserted between inversion circuit elements
US6504439B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 18, 1998 |
| Grant date | Jan 7, 2003 |
| Priority date | — |
| Expiry date | Feb 18, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K3/014
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A voltage controlled oscillation circuit with an oscillation frequency thereof controlled in accordance with an external voltage is disclosed. An odd number of inversion circuit elements such as inverters for inverting output signals thereof with respect to input signals thereto are connected in series with each other. An output side of the last-stage one of the odd number of the inversion circuit elements is connected to an input side of the first-stage one of the inversion circuit elements to thereby cause an oscillation. A plurality of oscillation frequency variable control units such as variable resistor circuit elements for changing an oscillation frequency in accordance with an external voltage are each inserted between each set of adjacent inversion circuit elements. A plurality of fixed resistor circuit elements each having a fixed resistance value are connected in parallel with a plurality of the oscillation frequency variable control units, respectively. The functions of both the variable resistor circuit elements and the fixed resistor circuit elements can be carried out at the same time by the use of a depletion type transistor or a transistor of a short channel type.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.