Globespan Virata Corporation

Conexant, Inc.

James J Zhao

Brian Horng

Nianxiong Tan

John M Ross

Christian Eichrodt

Benedict A Itri

Devin K Ng

Francis M Caster, Ii

An analog front-end circuit and method that supports multiple digital subscriber line (DSL) standards, including asymmetric digital subscriber line (ADSL) and very-high speed digital subscriber line (VDSL) is disclosed. The circuit incorporates multiple circuit blocks that can be selectively included into the transmit and receive paths of a DSL signal. It also permits selectable gain settings for signal amplifiers, and frequency bandwidth for signal filters that may be included in the transmit and receive paths. The receive path includes an analog-to-digital converter (ADC) that operates close to and exceeds the Nyquist sampling rate.

Wide-band analog front-end for DSL applications

A system and method for a filter tuner is presented. The system comprises a sequential logic, a register, a comparator, a first and second counter, a synchronizing logic, a first and second oscillator, a control logic, and a first and second combinational logic. The method comprises the steps of executing a calibration cycle of a filter tuner, executing a measurement cycle of the filter tuner, and tuning a filter with the filter tuner dependent on a determined cutoff frequency variation.

Filter tuner system and method

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Tustin, CA, United States of America

James J Zhao