Electrical transmission or interconnection systems – Capacitor
Patent
1998-07-23
2000-01-11
Gaffin, Jeffrey
Electrical transmission or interconnection systems
Capacitor
326 26, H02M 306, H03K 1716
Patent
active
060139587
ABSTRACT:
Disclosed is an integrated circuit having a plurality of combinations of an integrated unit capacitor connected in series with a controlled channel of an integrated transistor switch. The series-connected capacitor and switch combinations are connected in parallel and the switches include a control gate coupled to a bit output of a register via a control line. In this manner, the capacitance of the variable capacitor depends on what word is stored in the register. Control gates for a different number of capacitor and switch combinations are connected to each bit output, and the numbers are weighted using, e.g., a binary weighting scheme. The variable capacitor is coupled to a balanced signal line pair, with capacitor and switch combinations comprising a switch connected between two capacitors that are connected to a line of the balanced signal line pair. Such arrangement is highly linear and even order distortion is reduced. The disclosed integrated circuit arrangements reduce the sensitivity to noise on the control line of the device. Variations in voltage applied to the control line and thus to the control gate of the switch vary the resistance value of the switch when closed, yet affect the value of the capacitive portion of the impedance very little. The disclosed capacitors are useful in circuits that need to be accurately trimmed once (e.g., filters) and in circuits in which variable capacitance is required, such as voltage controlled oscillators (VCOs).
REFERENCES:
patent: 4499387 (1985-02-01), Konishi
patent: 4602222 (1986-07-01), Wynn
patent: 4716313 (1987-12-01), Hori et al.
patent: 5283631 (1994-02-01), Koerner et al.
patent: 5440156 (1995-08-01), Shou et al.
patent: 5574633 (1996-11-01), Prater
Khorramabadi, H., et al. "Baseband Filters for IS-95 CDMA Receiver Applications Featuring Digital Automatic Frequency Tuning," Digest of Technical Papers, p. 172-173 (1996).
Gaffin Jeffrey
Harman John M.
Huynh Kim
Lucent Technologies - Inc.
LandOfFree
Integrated circuit with variable capacitor does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Integrated circuit with variable capacitor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Integrated circuit with variable capacitor will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1464515