Sigma-Delta Integrator Circuit With Thermometric Reference Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing Sigma-Delta modulators face challenges in improving signal-to-noise ratio (SNR) while maintaining low power consumption and area, particularly in high-resolution analog-to-digital converters (ADCs) used in industrial applications.
Innovation Solution
An integrator circuit for Sigma-Delta modulators is designed with a differential amplifier, sampling and reference capacitors, and a switch control module, utilizing non-overlapping clock signals and thermometrically coded quantizer signals to manage switching, thereby improving SNR without increasing power or area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional Sigma-Delta modulators are used to improve signal-to-noise ratio, then measurement precision is improved, but power consumption and area increase
Solution Approach 1:
The integrator circuit is divided into two separate integrator modules (first and second integrator modules), each handling one differential input signal independently. This segmentation allows parallel processing of differential signals, improving signal-to-noise ratio through better integration accuracy while maintaining efficient power consumption by avoiding the need for a single complex high-power integrator.
2Measurement precision
If conventional Sigma-Delta modulators are used to improve signal-to-noise ratio, then measurement precision is improved, but device area increases
Solution Approach 1:
The circuit merges the functionality of two integrators into a shared architecture where both integrator modules share common components including the differential amplifier, clock signal generator, and switch control module. This merging approach achieves high signal-to-noise ratio performance equivalent to two separate integrators while occupying less area than two completely independent integrator circuits would require.
3Measurement precision
If multiple integrators are added to increase modulator order, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The differential amplifier and switch control module serve multiple functions: they are shared by both integrator modules, and the switch control module generates multiple clock phases (first and second non-overlapping clock signals) that coordinate both integrators. This multi-functionality enables the circuit to achieve higher effective modulator order while keeping the overall circuit complexity manageable through component sharing.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The proposed integrator circuit enhances SNR by 4.6 dB in ADCs, reduces input referred thermal noise, and maintains low power consumption, ensuring high linearity and accuracy in ADC drivers.
Implementation Method 1
a first integrator capacitor connected between the first input and the first output
Implementation Method 2
measures and integrates the error in a signal
Implementation Method 3
a second integrator capacitor connected between the second input and the second output
Implementation Method 4
measures and integrates the error in a signal
Implementation Method 5
first and second sampling capacitors connected between the first line and respective fifth and sixth switches
Implementation Method 6
a first plurality of reference capacitors connected between the first line and a respective first plurality of reference switches
Data Source
AI summary
The disclosure relates to an integrator circuit for a Sigma-Delta, ΣΔ, modulator, the integrator circuit comprising an integrator module comprising a differential amplifier, a sampling module comprising sampling capacitors and a reference module comprising first and second pluralities of reference capacitors connected between respective first and second lines and first and second pluralities of reference switches for connecting each of the reference capacitors to either a first reference terminal or a second reference terminal. In operation, the reference switches are switched according to a thermometrically coded quantizer signal.