Generation of differential signals
AssigneeNokia Technologies Oy
InventorsMartti Kalevi Voutilainen, Pirjo Marjaana Pasanen, Markku Anttoni Oksanen, Eira Tuulia Seppälä, Vladimir Alexsandrovich Ermolov
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Abstract
The invention relates to an apparatus comprising a differential driver module configured to generate at least one differential signal having steep rise and fall times for at least partially reducing common-mode noise. The invention also relates to a method for causing the differential driver to generate the signal and a system comprising the differential driver and a conductor module for transmission of the generated differential signal. A computer program for performing the method and a computer-readable medium is also part of the invention.
Claims25
An apparatus comprising:
- a switch driver to cause, based on an input signal, switching of a plurality of switches;
- and
- a differential driver comprising the plurality of switches coupled to at least two transmission lines to create a differential interface for sending digital data, wherein when the plurality of switches are switched, the differential driver generates at least one differential signal having rise and fall times, wherein the rise and fall times are determined by at least a switching time of the plurality of switches, wherein decreasing the rise and fall times to a range of times causes a reduction of a noise that is common to the at least two transmission lines, wherein each of the at least two transmission lines comprises a signal conductor, wherein the at least two transmission lines share a ground-plane, wherein the shared ground-plane is formed in a predetermined pattern to cause a reduction in amplitudes of frequency components of the noise above a predetermined frequency, and wherein the rise and fall times reduce amplitudes of frequency components of the noise below the predetermined frequency.
A method comprising:
- generating, by a switch driver, one or more control signals to cause, based on an input signal, switching of a plurality of switches;
- and
- generating, by a differential driver comprising the plurality of switches coupled to at least two transmission lines to create a differential interface for sending digital data, when the plurality of switches are switched, at least one differential signal having rise and fall times, wherein the rise and fall times are determined by at least a switching time of the plurality of switches, wherein decreasing the rise and fall times to a range of times causes a reduction of a noise that is common to the at least two transmission lines, wherein each of the at least two transmission lines comprises a signal conductor, wherein the at least two transmission lines share a ground-plane, wherein the shared ground-plane is formed in a predetermined pattern to cause a reduction in amplitudes of frequency components of the noise above a predetermined frequency, and wherein the rise and fall times reduce amplitudes of frequency components of the noise below the predetermined frequency.
A non-transitory computer-readable medium encoded with instructions that, when executed by at least one processor, cause operations comprising:
- generating, by a switch driver, one or more control signals to cause, based on an input signal, switching of a plurality of switches;
- and
- generating, by a differential driver comprising the plurality of switches coupled to at least two transmission lines to create a differential interface for sending digital data, when the plurality of switches are switched, at least one differential signal having rise and fall times, wherein the rise and fall times are determined by at least a switching time of the plurality of switches, wherein decreasing the rise and fall times to less than or equal to 35 picoseconds causes a reduction of a noise that is common to the at least two transmission lines, and wherein each of the plurality of switches includes an impedance element to cause impedance matching between the differential driver and the at least two transmission lines,
- wherein each of the at least two transmission lines comprises a signal conductor, wherein the at least two transmission lines share a ground-plane, wherein the shared ground-plane is formed in a predetermined pattern to cause a reduction in amplitudes of frequency components of the noise above a about 3 Gigahertz, and wherein the rise and fall times reduce amplitudes of frequency components of the noise below about 3 Gigahertz.
Dependencies are inferred from the claim text.