Industrial Consultancy & Sponsored Research (IC&SR) , IIT Madras
System and Method for Continuous-time Pipeline ADC With Reduced In-Band Transfer-function Droop
Categories for this Invention
Category- Analog-to-Digital Conversion (ADC) Systems
Applications – Communications, Industrial Automation
Industry – Telecommunications, Healthcare, Automotive Electronics
Market – The analog to digital converter market is anticipated to flourish at an average CAGR of 5.7% between 2023 and 2033 and is likely to reach a value of US$ 3.51 billion in 2023.
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Problem Statement
- The use of identical stages in a multi-stage Continuous-Time Pipelined (CTP) Analog-to-Digital Converter (ADC) leads to a notable in-band droop, causing a detrimental impact on both the Signal-to-Quantization Noise Ratio (SQNR) and overall conversion performance.
- While some existing multi-stage CTP ADCs utilize impedance scaling and second-order Butterworth stages to alleviate droop, they are limited in fully addressing the cumulative droop throughout the entire pipeline, especially when multiple stages are cascaded together.
- Moreover, the droop present in the filter transfer function within the signal band can result in a decrease in SQNR, especially affecting input frequency components near the band-edge frequency. This can greatly impede the converter’s reliability when it comes to various input variations.
Technology
- The present invention discloses a system and method for a continuous-time pipeline (CTP) analog-to-digital converter (ADC) which comprises the benefits of pipelining with continuous-time operation.
- The system incorporates at least one pipeline stage configured with non-identical amplifier filters, achieving a unique transfer function for each stage to reduce in-band transfer function droop.
- By utilizing non-identical residue amplifying filters in each pipeline stage, the system effectively reduces droop in the signal band, enhancing overall performance.
- The system features a computing application capable of determining the number of stages and filters, analyzing the non-identical transfer function, and determining transfer functions for non-identical pipeline stages.
- Unlike conventional approaches, the system is designed to realize an overall transfer function rather than selecting transfer functions for individual pipeline stages.
- The method provides flexibility by allowing the use of non-identical residue-amplifying filters such as Butterworth and Chebyshev filters, catering to user or application-specific requirements. The overall Butterworth design achieves higher Signal to Quantization Noise Ratio with lower droop at the band edge.
Key Features / Value Proposition
Market Advantage:
- Enhanced Performance: Non-identical transfer functions in each stage reduce in-band droop, improving Signal-to-Quantization Noise Ratio (SQNR) and overall ADC performance.
Key Features:
- Continuous-Time Operation: Leverages the benefits of continuous-time operation in a pipeline ADC, combining efficiency with high-speed conversion.
- Tailored Transfer Functions: Appropriate design of non-identical transfer functions per stage optimizes the equivalent anti-alias filter, maintaining high-frequency attenuation while minimizing in-band droop.
Competitive Edge:
- Adaptive Butterworth Function: Realizes an overall Butterworth transfer function, offering a competitive advantage over systems with individually chosen Butterworth transfer functions for each stage.
Industry Innovation:
- Integrated System Design: The CTP ADC system integrates non-identical filters and backend ADC seamlessly, presenting an innovative solution for improved performance without sacrificing design simplicity.
Questions about this Technology?
Contact For Licensing
sm-marketing@imail.iitm.ac.in
ipoffice2@iitm.ac.in
Research Lab
Prof. Shanthi Pavan
Department of Electrical Engineering
Intellectual Property
- IITM IDF Ref. 2301
- IN 441016 – Patent Granted
Technology Readiness Level
TRL – 4
Technology validated in lab scale.