A mixed-signal calibration technology for the pipeline A/D converter

Abstract

A mixed-signal calibration architecture and algorithm based upon 14bits 1.5b/s pipeline A/D converter is proposed1. The mixed-signal calibration algorithm consists of analog domain calibration and digital domain calibration. The analog-domain calibration algorithm adopts the level shifting technology to shift the input signal to lower voltage range. The digital output is reconstructed in the digital-domain after analog-to-digital conversion. The digital-domain calibration algorithm adopts code-by-code compensation technique and constructs a linear equation by the method of awaiting determined coefficients. An error calibration look-up table is acquired through the digital-domain calibration. A behavioral-level model of 14bits 1.5b/s pipeline ADC with mixed-signal calibration algorithm is established. The results show that the proposed calibration architecture and algorithm can effectively calibrate errors. The INL and DNL are reduced within ±0.5LSB. The SNDR is improved from 30.8dB to 84.5dB, and the ENOB is arrived to 13.74bits.