Oscillators – Solid state active element oscillator – Transistors
Reexamination Certificate
1999-11-02
2001-05-29
Kinkead, Arnold (Department: 2817)
Oscillators
Solid state active element oscillator
Transistors
C331S1170FE, C331S167000, C331S17700V, C331S03600C
Reexamination Certificate
active
06239665
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to the oscillator circuits, and more particularly, relates to a method and apparatus for switching in metal insulator metal (MIM) capacitors and field effect transistor (FET) tuning capacitors for oscillator circuits.
DESCRIPTION OF THE RELATED ART
Inductor capacitor (LC) tank oscillators offer superior jitter characteristics. However, the LC tank oscillators have a narrow frequency operating range. This makes it difficult to use LC tank oscillators in microprocessor applications due to the wide range of frequency operation required for debug and hardware base cycle time determination.
A need exists for an effective mechanism to change the range of an oscillator circuit, including LC tank oscillators.
SUMMARY OF THE INVENTION
A principal object of the present invention is to provide a method and apparatus for switching in metal insulator metal (MIM) capacitors and field effect transistor (FET) tuning capacitors for oscillator circuits. Other important objects of the present invention are to provide such method and apparatus for switching in metal insulator metal (MIM) capacitors and field effect transistor (FET) tuning capacitors for oscillator circuits substantially without negative effect and that overcome many of the disadvantages of prior art arrangements.
In brief, a method and apparatus are provided for switching in metal insulator metal (MIM) capacitors and field effect transistor (FET) tuning capacitors for oscillator circuits. Apparatus for switching in metal-insulator-metal (MIM) capacitors and field effect transistor (FET) tuning capacitors for oscillator circuits includes a first differential oscillator node and a second differential oscillator node. A plurality of metal-insulator-metal (MIM) capacitors are connected to the first differential oscillator nodes and a plurality of metal-insulator-metal (MIM) capacitors are connected to the second differential oscillator nodes. A respective switching transistor is connected in series with an associated one of the metal-insulator-metal (MIM) capacitors. Each switching transistor receives a decoding input and is arranged for providing an open or a ground connection for the associated one of the metal-insulator-metal (MIM) capacitors. A first field effect transistor (FET) tuning capacitor has a gate connected to the first differential oscillator node. A second field effect transistor (FET) tuning capacitor has a gate connected to the second differential oscillator node. Each of the first field effect transistor (FET) tuning capacitor and the second field effect transistor (FET) tuning capacitor having a source and a drain connected together and a control voltage applied to the connected source and drain for varying tuning capacitance.
REFERENCES:
patent: 5084685 (1992-01-01), Moller et al.
patent: 5179991 (1993-01-01), Takashima
patent: 5625325 (1997-04-01), Rotzoll et al.
patent: 5721517 (1998-02-01), Goma et al.
International Business Machines - Corporation
Kinkead Arnold
Pennington Joan
LandOfFree
Method and apparatus for switching in metal insulator metal... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for switching in metal insulator metal..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for switching in metal insulator metal... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2555775