Active linear amplifier inside transmitter module
AssigneeFinisar Corporation
InventorsThe'Linh Nguyen, Henry M. Daghighian
Life of this patent
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Abstract
In one example embodiment, a transmitter module includes a header electrically coupled to a chassis ground. First and second input nodes are configured to receive a differential data signal. A buffer stage has a first node coupled to the first input node and a second node coupled to the second input node. An amplifier stage has a fifth node coupled to a third node of the buffer stage and a sixth node coupled to a signal ground that is not coupled to the chassis ground. An optical transmitter has an eighth node coupled to a seventh node of the amplifier stage and a ninth node configured to be coupled to a voltage source. A bias circuit is configured to couple a fourth node of the buffer stage to a bias current source.
Claims18
A transmitter module with an active linear amplifier circuit, comprising:
- a header electrically coupled to a chassis ground;
- a first input node configured to receive a first data signal;
- a second input node configured to receive a second data signal that is complementary of the first data signal;
- a buffer stage having a first node coupled to the first input node and a second node coupled to the second input node, wherein the first node is at a first base terminal of a first transistor and the second node is at a second base terminal of a second transistor, a first emitter terminal of the first transistor is coupled to a second emitter terminal of the second transistor through a first resistor and a second resistor, and the first resistor and the second resistor are configured to be coupled to a current source between the first resistor and the second resistor;
- an amplifier stage having a fifth node coupled to a third node of the buffer stage and having a sixth node configured to be coupled to a signal ground, wherein the signal ground is not coupled to the chassis ground;
- an optical transmitter having an eighth node coupled to a seventh node of the amplifier stage and having a ninth node configured to be coupled to a voltage source;
- and
- a bias circuit configured to couple a fourth node of the buffer stage to a bias current source, wherein the fourth node is at a first collector terminal side of the first transistor and at a second collector terminal side of the second transistor;
- wherein:
- the buffer stage includes a third resistor, a differential amplifier, and a first bipolar transistor;
- the amplifier stage includes a second bipolar transistor and a fourth resistor;
- and
- the bias circuit includes a current mirror circuit, a plurality of transistors, and a plurality of resistors.
In an optoelectronic package, a linear signal amplification circuit, the circuit comprising:
- a first input node configured to receive a first data signal;
- a second input node configured to receive a second data signal that is complementary of the first data signal;
- a differential amplifier having an inverting input coupled to the first input node and a non-inverting input coupled to the second input node, wherein the inverting input is at a first base terminal of a first transistor and the non-inverting input is at a second base terminal of a second transistor, a first emitter terminal of the first transistor is coupled to a second emitter terminal of the second transistor through a first resistor and a second resistor, and the first resistor and the second resistor are configured to be coupled to a current source between the first resistor and the second resistor;
- a first bipolar transistor having a base terminal coupled to a first node of the differential amplifier;
- a second bipolar transistor having a base terminal coupled to an emitter terminal of the first bipolar transistor and having an emitter terminal configured to be coupled to a signal ground, wherein the signal ground is not coupled to a chassis ground;
- an optical transmitter having a first terminal configured to be coupled to a voltage source and a second terminal coupled to a collector terminal of the second bipolar transistor;
- a decoupling circuit having a first node coupled to the first node of the optical transmitter and a second node configured to be coupled to the signal ground;
- a bias circuit having a first node coupled to a second node of the differential amplifier and a second node configured to be coupled to a bias current source, wherein the second node is at a collector terminal side of two differential amplifier transistors, wherein the bias circuit includes a current mirror circuit, a plurality of transistors, and a plurality of resistors;
- and
- a buffer operational amplifier coupled between the first node of the bias circuit and the second node of the differential amplifier.
An optoelectronic package, comprising:
- a header assembly electrically coupled to a chassis ground;
- a linear signal amplification circuit included within the header and including:
- a first input node configured to receive a first data signal;
- a second input node configured to receive a second data signal that is complementary of the first data signal;
- a buffer stage having a first node coupled to the first input node and a second node coupled to the second input node, the buffer stage being configured to receive the first and second data signals from the first and second input nodes and convert the first and second data signals to a single-ended signal, wherein the first node is at a first base terminal of a first transistor and the second node is at a second base terminal of a second transistor, a first emitter terminal of the first transistor is coupled to a second emitter terminal of the second transistor through a first resistor and a second resistor, and the first resistor and the second resistor are configured to be coupled to a current source between the first resistor and the second resistor;
- an amplifier stage having a first node coupled to a third node of the buffer stage and having a second node configured to be coupled to a signal ground, wherein the signal ground is not coupled to the chassis ground, the amplifier stage being configured to receive the single-ended signal from the buffer stage and linearly amplify the single-ended signal to produce an amplified single-ended signal;
- and
- a bias circuit having a first node coupled to a fourth node of the buffer stage and having a second node configured to be coupled to a bias current source, wherein the bias circuit is configured to bias the linear signal amplification circuit, and the fourth node is at a first collector terminal side of the first transistor and at a second collector terminal side of the second transistor;
- and
- an optical transmitter coupled to the linear signal amplification circuit such that the optical transmitter can be driven by the amplified single-ended signal;
- wherein:
- the buffer stage includes a first resistor, a differential amplifier, and a first bipolar transistor;
- the amplifier stage includes a second bipolar transistor and a second resistor;
- and
- the bias circuit includes a current mirror circuit, a plurality of transistors, and a plurality of resistors.
Dependencies are inferred from the claim text.