Electric power conversion systems – Current conversion – Including d.c.-a.c.-d.c. converter
Reexamination Certificate
2002-05-08
2003-09-02
Nguyen, Matthew (Department: 2838)
Electric power conversion systems
Current conversion
Including d.c.-a.c.-d.c. converter
Reexamination Certificate
active
06614666
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to line communications and more particularly to a line driver capable of producing output drive signals with amplitudes greater than the supply voltage.
BACKGROUND OF THE INVENTION
Conventional line drivers commonly produce output signals with amplitudes that are limited by supply voltages. As integrated circuitry and process technologies improved, supply voltages reduced with associated reductions in the amplitudes of output drive signals.
Certain known schemes for increasing the amplitudes of output drive signals employ current-drive circuitry and transformer windings to produce output signals of greater amplitude than the supply voltages. However, such current-drive circuits commonly consume more power than voltage-drive circuitry and the inductive impedance inhibits rapid turn on/turn off operation.
SUMMARY OF THE INVENTION
In accordance with an illustrated embodiment of the present invention, a center-tapped transformer and associated drive circuitry deliver output drive signals with greater amplitude than the supply voltages, and with the associated drive circuitry greatly simplified to reduce power consumption and the processing involved for integrating the drive circuitry. P-MOS circuitry connected to a high-side supply voltage is eliminated in favor of transformer coupling from an N-MOS low-side supply voltage. The transformer also isolates the output drive signal from ground for enhanced versatility in connecting to communication lines. Output wave shapes for universal driver applications may be controlled in response to activation of a plurality of variable conduction elements in accordance with a selected logical sequence.
REFERENCES:
patent: 4280174 (1981-07-01), Sonda
patent: 5414309 (1995-05-01), Ichikawa et al.
patent: 5488554 (1996-01-01), Green
patent: 5895983 (1999-04-01), Motomura
patent: 6114844 (2000-09-01), Chang et al.
patent: 6316927 (2001-11-01), Chang et al.
Chang Menping
Chen June-Ying
Fenwick & West LLP
Micrel Inc.
Nguyen Matthew
LandOfFree
Universal output driver does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Universal output driver, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Universal output driver will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3062516