Altera Corporation

Xiaoyan Su

Sriram Narayan

Sergey Yuryevich Shumarayev

Wilson Wong

Sriam Narayan

Systems and methods are disclosed for employing an equalization technique that improves equalizer input sensitivity and which reduces power consumption. In particular, an equalization architecture is described that includes a continuous-time linear equalizer and a decision feedback equalizer, each with offset cancellation that enables the equalizer to be used at high data rates. In addition, the equalization structure has a power-saving mode for bypassing the decision feedback equalizer. These offset cancellation and power-saving features are enabled and controlled using programmable logic on a programmable device.

Reconfigurable equalization architecture for high-speed receivers

Equalizer circuitry on an integrated circuit ('IC') includes first, second, and third continuous time, equalizer stages connected in series. Each stage includes peaking inductor circuitry. The equalizer circuitry may further include controllably variable, static, DC mode offset voltage compensation circuitry and/or dynamic, continuous mode, offset voltage compensation circuitry for respectively reducing DC voltage offset and/or time-varying, continuous mode voltage offset between an output of the third equalizer stage and utilization circuitry to which that output is applied. The first equalizer stage may be preceded by termination circuitry having controllably variable impedance. Differential circuitry and signalling may be used for various circuit components. The equalizer circuitry is particularly useful for fabrication as part of a programmable IC, using 28 nm CMOS technology, and as a receiver equalizer for a high-speed serial data signal having a bit rate of 20-25 Gbps.

Receiver equalizer circuitry with offset voltage compensation for use on integrated circuits

A test driver transmitter drives a test signal through a resistive termination circuit to a first pin to test components on a board during a boundary scan test operation. A test receiver receives the test signal through a second pin and a pass gate coupled to the second pin during the boundary scan test operation. A test signal is transmitted to the test receiver during loopback operation through a loopback circuit.

Techniques for boundary scan testing using transmitters and receivers

One embodiment relates to a continuous-time circuit configured with an offset cancellation loop. The continuous-time circuit includes a multi-stage amplifier chain, including a first amplifier stage and a last amplifier stage, and an offset cancellation loop. The offset cancellation loop is configured to receive an output of the last amplifier stage and to provide an offset correction voltage signal to the first amplifier stage. The offset compensation loop may create one dominant pole and a single consequential parasitic pole so as to have greater stability and may advantageously achieve a second-order roll-off in response magnitude at higher frequencies. Other embodiments, aspects, and features are also disclosed.

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San Jose, CA, United States of America

Xiaoyan Su