On-chip AC coupled receiver with real-time linear baseline-wander compensation
AssigneeRambus Inc.
InventorYikui Jen Dong
Life of this patent
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Abstract
An on-chip AC coupled receiver with baseline wander compensation. The receiver may be used for either single ended or differential signals. The receiver includes an input terminal to receive an input signal. AC coupling circuitry is between the input terminal and a node and couples the input signal into a coupled signal at the node. A control loop senses low frequency signal content at the node and uses a linear buffer in adjusting the coupled signal at the node based on the low frequency signal content. The operation of the control loop compensates for potential baseline wander in the coupled signal. An input stage to recovers data from the coupled signal at the node.
Claims13
A receiver, comprising:
- a first input terminal to receive a first input signal;
- first alternating current (AC) coupling circuitry between the first input terminal and a first node, the first AC coupling circuitry coupling the first input signal into a first coupled signal at the first node;
- a data recovery circuit to recover data from the first coupled signal at the first node;
- and
- a control loop circuit comprising a low pass filter to filter the first coupled signal at the first node and a linear buffer having an input coupled to an output of the low pass filter, the linear buffer having a gain that is greater than zero and less than one, and the control loop circuit adjusts the first coupled signal at the first node based on an output of the linear buffer.
A method of operation in a receiver, the method comprising:
- receiving a first input signal at a first input terminal;
- coupling the first input signal into a first coupled signal at a first node using first AC coupling circuitry;
- low pass filtering the first coupled signal at the first node with a low pass filter;
- buffering an output of the low pass filter with a linear buffer having a gain that is greater than zero and less than one;
- adjusting the first coupled signal at the first node based on an output of the linear buffer;
- and
- recovering data from the first coupled signal at the first node.
Dependencies are inferred from the claim text.