Low voltage transmission line driver
AssigneePlato Labs, Inc.
InventorJoseph N. Babanezhad
Life of this patent
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Abstract
A high-speed low-voltage line-driver circuit implemented using various embodiments of high speed current-feedback opamps is disclosed. The line driver of the present invention uses a fully differential architecture whereby common-mode disturbances, such as noise due to substrate or power supply, are cancelled. The driver also uses a current-feedback approach to achieve larger bandwidth. In a specific embodiment, the current-feedback opamp used in the line driver of the present invention uses class A/B structure for both input and output stages.
Claims19
A current-feedback operational amplifier comprising:
- an input circuit adapted to receive an input current signal at a current-carrying node;
- a level shift circuit coupled to said input circuit in such a way as to not introduce additional parasitic nodes;
- a current source circuit coupled to said input circuit and said level shift circuit;
- and
- an output circuit coupled to said level shift circuit,
- wherein, a current supplied by said current source circuit is shared by both said input circuit and said level shift circuit.
A differential operational amplifier comprising:
- a positive-half circuit including:
- a first input circuit adapted to receive a first input current signal;
- a first level shift circuit coupled to said first input circuit;
- a first current source circuit coupled to said first input circuit and said first level shift circuit;
- and
- a first output circuit coupled to said first level shift circuit;
- a negative-half circuit including:
- a second input circuit adapted to receive a second input current signal;
- a second level shift circuit coupled to said second input circuit;
- a second current source circuit coupled to said second input circuit and said second level shift circuit;
- and
- a second output circuit coupled to said second level shift circuit;
- and
- a common-mode feedback circuit coupling an output of said first output circuit and an output of said second output circuit to said first and second current source circuits.
Dependencies are inferred from the claim text.