Drift canceling method and apparatus for analog to digital converters

摘要

A drift canceling method and apparatus is used in conjunction with an analog to digital converter. The drift canceling method and apparatus analyzes the duty cycle of the target analog to digital converter's most significant output data bit to determine if the average numeric value of the analog to digital converter's output data stream is data centered upon the analog to digital converter's numeric data range or if it is ranging above or below the data range center. If the average data value is above or below center, a servo error signal is generated which is added to the analog to digital converter's input signal to cause the analog to digital converter's average output data magnitude to slew towards the data range center. In this way, the average analog to digital converter output data offset is continuously canceled without interfering with the normal and continuous operation of the target analog to digital converter.