Delta-Sigma ADC Multiplexing for Multi-Input Conversion

Solution Overview

Problem

Existing ADC circuits require multiple converters for converting multiple analog signals, which increases complexity and cost.

Innovation Solution

An ADC circuit comprising a receiver circuit and a delta-sigma ADC, where the receiver circuit selects between multiple analog inputs based on a control signal, and the delta-sigma ADC converts the selected signal using a differential amplifier, integrator, quantizer, DAC, and digital filter circuit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple ADC circuits are used to convert multiple analog signals, then the conversion capability is improved, but the device complexity and cost increase

Engineering Contradiction:

Improveconversion capabilityVSAvoiddevice complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements a single ADC circuit that can handle multiple analog input signals through a receiver circuit with channel selection capability. The receiver circuit selects between multiple analog inputs based on control signals, allowing one ADC to perform the function of multiple ADCs, thereby reducing device complexity while maintaining multi-channel conversion capability

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines multiple analog input channels into a single conversion path using a receiver circuit that multiplexes the inputs. By merging the channel selection and ADC conversion functions into an integrated circuit, the system achieves multi-signal conversion without requiring separate ADCs for each channel

Inventive Principle:

Principle #5Merging (Combining)

2Adaptability or versatility

If multiple ADC circuits are used to convert multiple analog signals, then the conversion capability is improved, but the cost increases

Engineering Contradiction:

Improveconversion capabilityVSAvoidcomponent costs

Core Design Contradiction:

Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent implements a single ADC circuit that can handle multiple analog input signals through a receiver circuit with channel selection capability. The receiver circuit selects between multiple analog inputs based on control signals, allowing one ADC to perform the function of multiple ADCs, thereby reducing device complexity while maintaining multi-channel conversion capability

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines multiple analog input channels into a single conversion path using a receiver circuit that multiplexes the inputs. By merging the channel selection and ADC conversion functions into an integrated circuit, the system achieves multi-signal conversion without requiring separate ADCs for each channel

Inventive Principle:

Principle #5Merging (Combining)

3Device complexity

If a single ADC circuit is used for multiple analog signals, then the device complexity is reduced, but the conversion speed may decrease

Engineering Contradiction:

Improvedevice complexityVSAvoidconversion speed

Core Design Contradiction:

Device complexityVSSpeed

Solution Approach 1:

The patent applies over-sampling technique where the ADC circuit samples the analog signal at a rate higher than the minimum required conversion rate. This preliminary high-rate sampling allows the digital filter circuit to process and down-sample the data, achieving accurate conversion results while maintaining fast conversion speed and reducing the impact of channel switching

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses periodic over-sampling and digital filtering to maintain high conversion speed. By sampling periodically at high rates and using digital filter circuits to process the sampled data, the system achieves both fast conversion and high accuracy without being limited by the sequential channel switching speed

Inventive Principle:

Principle #19Periodic action

Data Source

PatentUS20250038763A1Analog-to-digital converter circuit, digital filter circuit, and control method thereof

Publication Date: 2025.01.30 NUVOTON

AI summary

An analog-to-digital converter (ADC) circuit including a receiving circuit and a delta-sigma ADC is provided. The receiving circuit receives a first analog input and a second analog input, and uses the first or second analog input as an output signal according to a control signal. The delta-sigma ADC converts the output signal to input data. The delta-sigma ADC over-samples the input data to generate a plurality of sampling results and stores the sampling results. The delta-sigma ADC generates output data according to the sampling results.