Low-power analog decision feedback equalizer
AssigneeNVIDIA Corporation
InventorsYi-Chieh Huang, Hao-Wei Hung, Ying Wei
Life of this patent
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Abstract
A communications circuit includes a receiver (RX) frontend coupled to an RX deserializer and the RX frontend includes a decision feedback equalizer coupled directly between an output and an input of the RX frontend. The decision feedback equalizer may include a first inverter and a series combination of a first resistor and a first capacitor coupled in series with the first inverter.
Claims19
A communications circuit comprising:
- a receiver (RX) frontend coupled to an RX deserializer;
- wherein the RX frontend comprises a decision feedback equalizer coupled directly between an output and an input of the RX frontend, the decision feedback equalizer comprising:
- a first inverter;
- and
- a series combination of a first resistor and a first capacitor coupled in series with the first inverter, wherein the series combination of the first resistor and the first capacitor combined with an input resistor of the RX frontend operates as a bandpass filter configured to coincide with a first post cursor output by the RX frontend.
A communications device comprising:
- a receiver (RX) frontend coupled to an RX deserializer, wherein the RX frontend comprises:
- a single-to-differential signal amplifier;
- a trans-admittance stage (TAS) coupled to the single-to-differential signal amplifier;
- a trans-impedance amplifier (TIA) coupled to the TAS;
- and
- a decision feedback equalizer coupled directly between an output of the TIA and an input to the single-to-differential signal amplifier, wherein the decision feedback equalizer comprises:
- a first inverter coupled to a positive output of the TIA;
- and
- a series combination of a first resistor and a first capacitor coupled in series with the first inverter and to a positive differential tap point of the input to the single-to-differential signal amplifier.
A method of operating a communications circuit comprising a receiver (RX) frontend including an analog decision feedback equalizer coupled to an RX deserializer, wherein the method comprises:
- coupling a first feedback loop of the analog decision feedback equalizer directly between a positive output of the RX frontend to a positive differential tap point of an input to a single-to-differential amplifier of the RX frontend;
- and
- coupling a second feedback loop of the analog decision feedback equalizer directly between a negative output of the RX frontend to a negative differential tap point of the input to the single-to-differential amplifier of the RX frontend.
Dependencies are inferred from the claim text.