Qualcomm Incorporated

Darius Valaee

Patrick Isakanian

Srivatsan Thiruvengadam

A method for equalizing a data signal includes providing a data signal to a pair of input transistors that provides an output signal, contributing to the output signal, a first current or voltage that has a magnitude determined by a first weighted feedback signal using a first decision-feedback circuit that includes a first pullup circuit coupled to a drain of a first input transistor, and a first pulldown circuit coupled to the drain of the first input transistor, and contributing to the output signal, a second current or voltage that has a magnitude determined by a second weighted feedback signal using a second decision-feedback circuit that includes a second pullup circuit coupled between a drain of a second input transistor and the first voltage rail, and a second pulldown circuit coupled between the drain of the second input transistor and a second voltage rail.

Parallel direct-feedback decision-feedback equalizer for high-speed low-voltage wireline links

An integrated circuit (IC) including a first transceiver interface circuit extending longitudinally in a first direction substantially perpendicular to a second direction parallel to edge of the IC, wherein the first transceiver interface circuit comprises a first T-coil; and a second transceiver interface circuit extending longitudinally in the first direction, wherein the second transceiver interface circuit is staggered from the first transceiver interface circuit along the second direction, wherein the second transceiver interface circuit includes a second T-coil, and wherein the second T-coil is offset from the first T-coil along the first direction.

Integrated circuit integration of T-coils at interfaces to communication links

An input stage of a comparator includes a first transistor, wherein a gate of the first transistor is coupled to a first input of the input stage, a second transistor, wherein a gate of the second transistor is coupled to a second input of the input stage, a third transistor coupled in series with the first transistor, and a fourth transistor coupled in series with the second transistor. The input stage also includes a fifth transistor, wherein a gate of the fifth transistor is configured to receive a first decision feedback signal, and a drain of the fifth transistor is coupled to a gate of the third transistor. The input stage further includes a sixth transistor, wherein a gate of the sixth transistor is configured to receive a second decision feedback signal, and a drain of the sixth transistor is coupled to a gate of the fourth transistor.

Clocked comparator with series decision feedback equalization

In certain aspects, a comparator includes an input stage and a regeneration stage. The input stage includes a first input circuit coupled to a first node and a second node, a first switching transistor configured to enable the first input circuit if a previous bit value is one, a second input circuit coupled to the first node and the second node, and a second switching transistor configured to enable the second input circuit if the previous bit value is zero. The regeneration stage includes a first inverter, a second inverter cross coupled with the first inverter, a first drive transistor coupled to the first inverter, wherein a gate of the first drive transistor is coupled to the second node, and a second drive transistor coupled to the second inverter, wherein a gate of the second drive transistor is coupled to the first node.

Decision feedback equalizer for low-voltage high-speed serial links

An equalizing transmitter coupled to a serial transmission line has a driver circuit coupled between an input signal and the serial transmission line, the driver circuit being configured to receive power at a first voltage level. The equalizing transmitter has one or more helper circuits, each helper circuit being configured to receive a control signal and to pull the serial transmission line to a second voltage level when a pulse is present in the control signal. The second voltage level may be greater than the first voltage level. The equalizing transmitter has one or more pulse generation circuits, each pulse generation circuit being configured to receive the input signal and a delayed version of the input signal and to provide the pulse in the control signal when a difference in voltage state is detected between the input signal and the delayed version of the input signal.

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San Diego, CA, United States of America

Darius Valaee