Method of calibrating a slicer in a receiver or the like

摘要

A method of calibrating data slicer-latches in a receiver to remove offset errors in the slicer-latches. A known voltage is applied to all but one of the inputs of the slicer-latch. The remaining input receives an offset cancelation voltage from a DAC is stepped upward from a minimum voltage until the slicer-latch output transitions by incrementing a codeword to the DAC and the codeword that resulted the transition is saved. Then the offset cancelation voltage is swept downward in steps from a maximum voltage until the slicer-latch output transitions and the codeword that caused the transition is averaged with the stored codeword. The average of the codewords is applied to the DAC to generate the offset cancelation voltage used during normal operation of the receiver.

主权项

1. A method of reducing offset errors in a data slicer having at least two analog inputs and a digital output, the method comprising the steps of:
a) applying a fixed signal to a first one of the data slicer inputs, the fixed signal having a known value; b) applying a calibration signal to a second one of the data slicer inputs, the calibration signal having a value; c) setting the value of the calibration signal to a first starting value; d) changing the first starting value of the calibration signal by an amount having a first polarity; e) repeating step d) until an output of the slicer-latch changes state; f) storing the changed value of the calibration signal as a first value; g) setting the value of the calibration signal to a second starting value different from the first starting value; h) changing the second starting value of the calibration signal by a second amount having a second polarity opposite the first polarity; i) repeating step h) until the output of the data slicer changes state; j) averaging the changed value of the second starting value of the calibration signal with the first value to form a calibration signal average value; k) applying the calibration signal average as the calibration signal to the second one of the data slicer input; l) removing the fixed signal from the first one of the data slicer input; and m) applying an input signal to the first one of the data slicer input.