Analog-digital converter with sample hold and MDAC (Multiplying Digital-to-Analog Conversion) sharing capacitance and operational amplifier in time sharing way

Abstract

The invention discloses a high-speed production line analog-digital converter comprising a reference voltage source, a clock generation module, a first-grade analog-digital conversion module, a sequential L-1 grade sequentially-connected analog-digital conversion module and a last-grade speed flash type analog-digital conversion module, wherein the first-grade analog-digital conversion module is merged by a sample hold module and a first-grade MDAC (Multiplying Digital-to-Analog Conversion) module; each grade analog-digital conversion module and the speed flash type analog-digital conversion module are connected with a correction and calibration module; the first-grade analog-digital conversion module comprises the sample hold module, the MDAC, an operational amplifier and a subADC (sub Analog-to-Digital Conversion) module; the clock generation module generates a four-phase nonoverlapping clock signal; and the sample hold module and the first-grade MDAC module share the OP (Operational Amplifier) in a time sharing way and also share a same capacitor in the time sharing way. The invention reduces the load capacitance of the OP of the sample hold module and the MDAC module more than 60 percent, the design difficulty and the circuit power consumption and increases the ADC speed of a production line.

Description

technical field [0001] The invention relates to a pipelined analog-to-digital conversion module, in particular to a high-speed pipelined analog-to-digital converter in which the sampling and holding module and the first-stage gain digital-to-analog conversion module MDAC capacitor are time-shared and the operational amplifier is time-shared. Background technique [0002] Analog-to-digital conversion module, also known as A / D converter or Analog-to-Digital Converter, referred to as ADC, is a device that converts continuous analog signals into discrete digital signals. In order to ensure the accuracy of the system processing results, the A / D converter must have sufficient conversion accuracy; if the real-time control and detection of fast-changing signals are to be realized, the A / D converter also requires a higher conversion speed. Conversion accuracy and conversion speed are important technical indicators to measure the A / D converter. [0003] Inspired by the way of pipelin...

AI Technical Summary

Problems solved by technology

The traditional method, as shown in Figure 1, is to use the time-sharing method of the sampling and holding stage and the first-stage gain digital-to-analog conversion module MDAC operational amplifier. In this method, the first-stage gain digital-to-analog conversion module MDAC sampling capacitor and the sampling and holding stage The feedback capacitor needs to be connected to the output terminal of the amplifier at the same time, which increases the equivalent load of the output terminal of the operational amplifier, and also increases the requirements for the input transconductance of the operational amplifier, which increases the difficulty of design and the power consumption of the circuit

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