Class AB source follower
AssigneeAgere Systems Inc.
InventorsStephen J. Franck, Ranganathan Desikachari, Matthew Clapp
Life of this patent
Estimating the term…
Abstract
Various source follower circuits and methods for implementing such are disclosed. As one example, a class AB source follower circuit is disclosed that includes a source follower circuit that is actively biased. The dynamic biasing allows the source follower circuit to sustainably sink a DC current. In some instances of the embodiments, the class AB source follower circuits are operable to source and sink both AC and DC currents.
Claims20
A compound source follower circuit, wherein the compound source follower circuit comprises:
- an input transistor, wherein a gate of the input transistor is electrically coupled to an input;
- a positive drive transistor;
- a negative drive transistor;
- an output, wherein the output is electrically coupled to both the negative drive transistor and to the positive drive transistor;
- a capacitor, wherein the capacitor couples the negative drive transistor to the positive drive transistor;
- and
- a dynamic bias circuit, wherein the dynamic bias circuit is operable to vary a voltage difference between the positive drive transistor and the negative drive transistor sufficient to sustainably adjust an output drive to respond to a change in quiescent load.
A class AB source follower circuit, wherein the circuit comprises:
- a source follower circuit, wherein the source follower circuit is actively biased with an active bias operable to allow the source follower circuit to both sustainably sink and source DC current.
A method for implementing a class AB source follower circuit, wherein the method comprises:
- providing a source follower circuit;
- and
- dynamically biasing the source follower circuit such that the source follower circuit is capable of both sustainably sinking and sourcing DC current.
Dependencies are inferred from the claim text.