Digital Calibration and Correction Methods for CMOS-ADCs
Details
Along with miniaturization of CMOS-LSIs, control methods in the LSIs have been highly developed. The most predominant method is to make observed values digitized as in early stage as possible, and to use digital control methods. Thus many kinds of analog-to-digital converters (ADCs) have been developed such as temperature, time, delay and frequency converters. ADCs are the easiest circuit to introduce digital correction methods because the outputs of these are digital. All sorts of calibration methods were developed and the calibration drastically improved figure of merits by alleviating margins for device variations. These calibration and correction not only overcome circuit's weak points but also gives chance us to develop quite new circuit topologies and systems. In this paper, several techniques of digital calibration and correction for major analog to digital converter are described, such as pipelined ADC, delta-sigma ADC and successive approximation ADC.
