Output driver for an integrated circuit
AssigneeCadence Design Systems, Inc.
InventorsWilliam P. Evans, Luca Ravezzi, Alberto Baldisserotto
Life of this patent
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Abstract
A circuit and method for driving the output signal, having a common-mode voltage and an output swing, of an integrated circuit. In accordance with an aspect of an embodiment of the present invention, a first power supply provides the termination voltage for the output signal and a second power supply provides the power to set the common mode voltage. In accordance with another aspect, the common-mode voltage and the output swing are programmable.
Claims32
A method for driving a differential output signal, having a common mode voltage and an output swing for an integrated circuit, comprising:
- providing a first power supply for a termination voltage for the differential output signal;
- providing a second power supply to adjust the common mode voltage;
- and
- adjusting the common mode voltage;
- wherein the first power supply generates lower voltage compared to the second power supply.
A method for driving a differential output signal, having a common mode voltage and an output swing, for an integrated circuit, comprising:
- selecting a standard having a common mode voltage and an output swing from the group consisting of:
- a low voltage differential signaling (LVDS) standard and a low voltage transistor to transistor logic (LVTTL) standard;
- adjusting the common mode voltage to the common mode voltage of the selected standard;
- and
- adjusting the output swing to the output swing of the selected standard.
A circuit for driving a differential output signal, having a common mode voltage and an output swing for an integrated circuit, comprising:
- a means for providing a first power supply for a termination voltage for the differential output signal;
- a means for providing a second power supply to adjust the common mode voltage;
- and
- a means for adjusting the common mode voltage;
- wherein the first power supply generates a lower voltage compared to the second power supply.
A circuit for driving a differential output signal, having a common mode voltage and an output swing, for an integrated circuit, comprising:
- means for selecting a standard having a common mode voltage and an output swing from the group consisting of:
- a low voltage differential signaling (LVDS) standard and a low voltage transistor to transistor logic (LVTTL) standard;
- means for adjusting the common mode voltage to the common mode voltage of the selected standard;
- and
- means for adjusting the output swing to the output swing of the selected standard.
An apparatus for driving an output signal, having a common mode voltage and an output swing, for an integrated circuit, comprising:
- a pair of output terminals, wherein the pair of output terminals provides the output signal;
- a first power supply coupled to the pair of output terminals, wherein the first power supply provides a termination voltage for the output signal;
- a second power supply coupled to the pair of output terminals, wherein the second power supply provides power to set the common mode voltage for the output signal;
- and
- a programmable current source coupled with the pair of output terminals for controlling the output swing.
Dependencies are inferred from the claim text.