Low voltage differential swing (LVDS) signal driver circuit with low PVT sensitivity
AssigneeNational Semiconductor Corporation
InventorsRichard W. Cook, Stephen J. O'Brien, Roy L. Yarbrough
Life of this patent
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Abstract
A low voltage differential swing (LVDS) signal driver having a constant output differential voltage (Vod) over variations in circuit fabrication processes, power supply voltages and operating temperatures (PVT). The minimum and maximum values of the LVDS output signal are monitored and, based upon the difference between them, a signal is provided to the circuit to control the LVDS output signal such that its peak-to-peak value is maintained at a determined value.
Claims12
An apparatus including a low voltage differential swing (LVDS) signal driver, comprising:
- differential signal driver circuitry that receives a control signal and in response thereto receives and converts a dual differential input signal to a LVDS signal having minimum and maximum peak signal values;
- and
- feedback circuitry, coupled to said differential signal driver circuitry, that receives said LVDS signal and in response thereto provides said control signal, wherein a difference between said minimum and maximum peak signal value, is maintained at a predetermined value;
- wherein said feedback circuitry comprises
- signal peak detection circuitry that receives said LVDS signal and in response thereto provides first and second detected peak signals representing said minimum and maximum peak signal values, and
- control circuitry, coupled to said signal detection circuitry, that receives said first and second detected peak signals and in response thereto provides said control signal.
An apparatus including a low voltage differential swing (LVDS) signal driver, comprising:
- signal driver means for receiving a control signal and in response thereto receiving and converting a dual differential input signal to a LVDS signal having minimum and maximum peak signal values;
- and
- feedback means for receiving said LVDS signal and in response thereto providing said control signal and maintaining difference between said minimum and maximum peak signal values at a predetermined value;
- wherein said feedback means comprises
- peak detector means for detecting said LVDS signal and providing first and second detected peak signals representing said minimum and maximum peak signal values, and
- controller means for receiving said first and second detected peak signals and in response thereto providing said control signal.
A method for generating a low voltage differential swing (LVDS) signal driver, comprising:
- receiving a control signal;
- receiving a dual differential input signal;
- converting said dual differential input signal to a LVDS signal having minimum and maximum peak signal values in response to said control signal;
- and
- generating said control signal in response to said LVDS signal and thereby maintaining a difference between said minimum and maximum peak signal values at a predetermined value by
- generating, in response to said LVDS signal, first and second detected peak signals representing said minimum and maximum peak signal values, and
- generating said control signal in response to said first and second detected peak signals.
Dependencies are inferred from the claim text.