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US 8,009,824 B2Granted
Line driver with active termination
AssigneeBroadcom Corporation
InventorsJiangfeng Wu, Tianwei Li, Arnoldus Venes
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AssigneeBroadcom Corporation
InventorsJiangfeng Wu, Tianwei Li, Arnoldus Venes
Estimating the term…
A line driver comprises a driving amplifier receiving an input of the line driver, a current sense resistor connected between the driving amplifier output and the line driver output, and a feedback amplifier sensing the voltage across the current sense resistor and providing a corresponding feedback voltage that is proportional to the output current to the driving amplifier, thereby determining an output impedance at the line driver output. Precise output impedance can be realized by using a high precision resistor as the current sense resistor, and using resistive feedback amplifiers with accurate gains as the driving and feedback amplifiers. The resistance of the current sense resistor can be substantially less than the line driver output impedance, and the driving amplifier output voltage swing can be substantially less than twice the line driver output voltage swing.
A line driver comprising:
Dependencies are inferred from the claim text.
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From the US filing history. Foreign family members aren’t listed.
Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors: using different frequency bands for speech and…
Arrangements for coupling to transmission lines: arrangements specific to the transmitter end
Arrangements for coupling to transmission lines: arrangement for terminating transmission lines
Telephonic communication
About 3 years 8 months of term left · ends 30 Jun 2030 (estimated)
1. Field of the Invention
The present invention is generally in the field of electrical circuits. More particularly, the invention is in the field of line drivers.
2. Background Art
FIG. 1 illustrates a circuit diagram of an exemplary conventional line driver coupled to a load resistor.
FIG. 2 illustrates a circuit diagram of an exemplary line driver coupled to a load resistor in accordance with one embodiment of the present invention.
FIG. 3 illustrates a circuit diagram of an exemplary line driver coupled to a load resistor in accordance with one embodiment of the present invention.
The present invention is directed to a line driver with active termination. The following description contains specific information pertaining to the implementation of the present invention. One skilled in the art will recognize that the present invention may be implemented in a manner different from that specifically discussed in the present application. Moreover, some of the specific details of the invention are not discussed in order not to obscure the invention.
The drawings in the present application and their accompanying detailed descriptions are directed to merely exemplary embodiments of the invention. To maintain brevity, other embodiments of the present invention are not specifically described in the present application and are not specifically illustrated by the present drawings.
FIG. 1 shows a circuit diagram of an exemplary conventional line driver coupled to a load resistor. Circuit 100 includes conventional line driver 102, transmission line 104, and load resistor 106. Conventional line driver 102, which is a voltage mode line driver, includes voltage amplifier 108 and termination resistor 110. Conventional line driver 102 receives differential input voltages VIP 112 and VIN 114 and provides output voltage VOUT 116. Conventional line driver 102 can be utilized in audio, video, and multimedia applications, for example.