Offset Compensation for Balanced Signal Communication Zero-Crossing Threshold Detector
Original Publication Date: 1983-Dec-01
Included in the Prior Art Database: 2005-Feb-08
A differential voltage comparator is utilized to compensate for crossover distortion in a communications circuit. Offset distortion/imbalance in high gain comparators is eliminated without requiring potentiometers or cascaded AC coupled gain stages. Binary communication receivers typically operate with signals in the microvolt or millivolt range and must be amplified to logic levels. An optimum sampling threshold is usually halfway between the one level and zero level. Balanced coding techniques, such as biphase (e.g., Manchester), are used to insure an equal number of ones and zeroes in the data format so that a threshold setting can easily be established by AC coupling to a threshold detector and using a ground potential as the sampling reference.