Pipeline ADC Switchable Conductance Circuit Without High-Gain Op-Amps
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pipeline analog-to-digital converters face challenges in implementing high-gain, high-precision, and high-bandwidth operational amplifiers, especially in deep submicron technology, which are power-intensive and reduce operating bandwidth, making them unsuitable for high-speed and high-resolution applications.
Innovation Solution
The implementation of a pipeline analog-to-digital converter using switchable conductance circuitry that eliminates the need for inter-stage gain functionality, utilizing PMOS and NMOS transistors and a non-overlapping clock scheme, with switchable conductance digital-to-analog conversion circuitry that switches between conductance values based on comparator outputs, allowing for high-speed and high-resolution conversion without high-gain operational amplifiers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high-gain, high-precision operational amplifiers are used for inter-stage gain in pipeline ADC, then measurement precision is improved, but power consumption increases and operating bandwidth decreases
Solution Approach 1:
The patent removes the inter-stage gain operational amplifier from the pipeline ADC architecture entirely. Instead of using a high-gain operational amplifier for inter-stage gain, the invention uses a switched-capacitor circuit with a unity-gain operational amplifier followed by a gain stage implemented with a switchable conductance digital-to-analog conversion circuit, thereby eliminating the need for high-power high-gain amplifiers while maintaining conversion precision.
Solution Approach 2:
The patent changes the gain implementation from analog (operational amplifier-based) to digital (switchable conductance-based). The gain stage uses a digital-to-analog conversion circuit with switchable conductance values controlled by digital signals, allowing precise gain control without the power consumption and bandwidth limitations of high-gain operational amplifiers.
2Measurement precision
If high-gain, high-precision operational amplifiers are used for inter-stage gain in pipeline ADC, then measurement precision is improved, but operating bandwidth decreases
Solution Approach 1:
The patent removes the high-gain operational amplifier from the signal path, replacing it with a switched-capacitor circuit and digital-to-analog conversion stage. This extraction eliminates the bandwidth-limiting effect of high-gain amplifiers while preserving precision through digital control of the gain stage.
Solution Approach 2:
The patent substitutes the analog operational amplifier-based gain stage with a digital control mechanism. The gain is controlled by digital signals that switch conductance values in the digital-to-analog conversion circuit, replacing the continuous analog adjustment of operational amplifiers with discrete digital control, thereby increasing operating bandwidth while maintaining precision.
3Measurement precision
If switched-capacitor circuitry with high-gain operational amplifiers is used, then conversion precision is improved, but device complexity increases
Solution Approach 1:
The patent extracts and removes the complex high-gain operational amplifier stage from the circuit, replacing it with simpler switched-capacitor circuits and digital-to-analog conversion stages. This reduces device complexity while maintaining precision through digital control mechanisms.
4Measurement precision
If external reference voltages are required for pipeline ADC operation, then measurement precision is maintained, but device complexity and power consumption increase
Solution Approach 1:
The patent implements self-service by generating the required reference voltages internally within the pipeline ADC stages. The switched-capacitor circuits and digital-to-analog conversion stages generate their own reference voltages from the input signal and internal clock signals, eliminating the need for external reference voltage sources and reducing both device complexity and power consumption.
Data Source
AI summary
A pipeline analog-to-digital converter is disclosed. An example of a pipeline analog-to-digital converter comprises a plurality of stages. Each of the plurality of stages comprises an analog-to-digital conversion circuit comprising a comparator configured to produce an n-bit digital domain output; and a switchable conductance digital-to-analog conversion circuit operatively coupled to the comparator and configured to switch between at least two conductance values in response to a value of the n-bit digital domain output.