Variable resistor voltage driver with self-noise compensation circuit
AssigneeAquantia Corporation
InventorRamin Farjadrad
Life of this patent
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Abstract
A multi-PAM line driver circuit to drive input data along a transmission line from a voltage source is disclosed. The driver circuit includes a voltage source to supply a regulated voltage and a regulator current. A main branch is coupled between the voltage source and the transmission line and includes variable impedance circuitry. The main branch draws a drive current from the voltage source. A compensating branch is coupled to the voltage source in parallel with the main branch and includes a second variable impedance circuit to draw a compensating current from the voltage source based on the drive current, such that a sum of the drive current and the compensating current is substantially constant during the transmission of the input data.
Claims12
A multi-PAM line driver circuit to drive multi-PAM input data along a transmission line, the driver circuit comprising:
- a voltage source to supply a regulated voltage;
- a main branch having a first segment coupled between the voltage source and the transmission line, the first segment including a first variable impedance circuit, the main branch having a second segment coupled between a ground node and the transmission line and including a second variable impedance circuit, the main branch drawing a consumed drive current from the voltage source;
- and
- a compensating branch coupled to the voltage source in parallel with the main branch and including a third variable impedance circuit to draw a consumed compensating current from the voltage source based on the consumed drive current, such that a sum of the consumed drive current and the consumed compensating current through the voltage source is substantially constant during the transmission of the multi-PAM input data.
A method comprising:
- driving multi-PAM input data along a transmission line by
- supplying consumed drive current along a main branch between a voltage source and a reference node, the main branch having a first segment coupled between the voltage source and the transmission line and including a first variable impedance circuit, the main branch further including a second segment coupled between the reference node and the transmission line and including a second variable impedance circuit;
- and
- supplying consumed auxiliary current along an auxiliary compensating branch coupled in parallel with the main branch, wherein a sum of the consumed drive and auxiliary currents through the voltage source is substantially constant.
Dependencies are inferred from the claim text.