US 7,352,207 B2 · Output driver with common mode feedback

Abstract

A complementary metal-oxide semiconductor output driver provides a differential output signal having a particular differential voltage swing and a particular common mode voltage to a differential output node for various types of load circuits coupled to the differential output node. The load circuit may have any impedance within a particular impedance range. A current source provides a current with a variable current component that adjusts the differential voltage swing of the differential output signal. A common mode feedback circuit adjusts the common mode voltage of the differential output signal by sourcing current to the differential output node or sinking current from the differential output node. At least a portion of a current flowing into a load circuit coupled to the differential node is provided by the current source, thereby reusing current from the current source.

Claims29

Dependent claims

An integrated circuit comprising:

a buffer circuit including a differential input node, a common node, a differential pair of devices coupled to the differential input node and the common node, a differential output node, and a current source coupled to the common node,
wherein the buffer circuit is configured to provide a differential output signal on the differential output node, the differential output signal having a differential voltage swing and a common mode voltage and being provided based on at least a differential input signal on the differential input node, a particular differential voltage swing, a particular common mode voltage, the differential voltage swing of the differential output signal, and the common mode voltage of the differential output signal.

Dependencies are inferred from the claim text.

Output driver with common mode feedback

Life of this patent

Output driver with common mode feedback

Life of this patent

Abstract

Claims29