A calibration technique for high-speed high-resolution A/D converters

Digital calibration has become essential to meet challenging A/D converter specifications for future telecommunication systems. Next generation apparatuses will require converters with resolution as high as 12 bit and very high linearity (>90 dB) at more than 40 MHz sampling rate. This paper proposes a correction technique suitable for off-line operation. A statistical method determines the ADC actual transfer characteristic and a digital look-up table performs the subsequent correction. Extensive experimental results show an average improvement of 12 dB (2 bit) in the converter linearity permitting commercial components to satisfy specifications of emerging telecommunication architectures. Performances are maintained over a significant temperature range and with ageing.