A pipelined analog-to-digital converter comparator offset front calibration circuit and method

Abstract

A pipelined analog-to-digital converter comparator offset calibration circuit and method, including a current source I1 and an adjustable resistor string unit array, the adjustable resistor string unit array includes N adjustable resistor string units RESL1-RESLN, and the power supply VDD and The current source I1 and the adjustable resistor string units RESL1 - RESLN are sequentially connected in series between the grounds. The adjustable resistor string units RESL1 - RESLN have the same structure and adjustable resistance. The adjustable resistor string unit includes 4 trimming resistors R1~R4, 5 switches SW1~SW5, 1 binary alternative switch DSW, comparator COMP, accumulator ACCU, threshold decision device THR and bidirectional shift register SHREG. The invention divides the traditional divider resistor into four for fine-tuning the offset voltage of the comparator without introducing additional static power consumption, and is especially suitable for low-power consumption design.

Description

Technical field [0001] The present invention relates to the field of integrated circuits, is a pipelined analog-to-digital converter comparator offset front-end calibration circuit and method, mainly used in low-power pipelined analog-to-digital converters. Background [0002] In the design of pipelined analog-to-digital converters, device mismatches due to process deviations and imbalances in the parasitic inductance capacitance of the switch can cause the comparator to be out of balance, which seriously affects the performance of the analog-to-digital converter. Generally, increasing the size of the device can reduce its offset but will lead to a serious increase in power consumption, so how to reduce the comparator offset without increasing the power consumption is one of the research focuses of the current pipelined analog-to-digital converter design. [0003] The traditional comparator offset calibration mainly uses an analog method to measure the offset voltage of the comp...

AI Technical Summary

Problems solved by technology

[0004] In recent years, many digital calibration methods for comparator offset calibration have appeared, but they mainly focus on solving the static offset error of the comparator, but cannot solve the dynamic offset error of the comparator.

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