Capacitor-Sharing DAC Circuit for Low-Noise Signal Conversion
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Solution Overview
Problem
Existing digital to analog converters, particularly those using delta sigma modulation, face challenges in achieving optimal total harmonic distortion and signal to noise ratio, and require additional components or complex switch configurations to address noise shaping and flicker noise modulation.
Innovation Solution
The proposed digital to analog converter employs a configuration of capacitors and operational amplifiers with switch modules controlled by clock signals and digital codes, allowing for parallel connections during specific periods to achieve efficient charge sharing and noise modulation without additional switches, and can process both single-bit and multi-bit codes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If delta sigma modulation with noise shaping technology is used, then signal to noise ratio is improved, but device complexity increases due to additional components and complex switch configurations
Solution Approach 1:
The patent merges the first and second capacitors in parallel with the operational amplifier during the second period, eliminating the need for additional switches. This combining approach maintains the noise shaping functionality while reducing device complexity by using a shared switch configuration for both capacitors.
Solution Approach 2:
The switch is designed to perform multiple functions: it controls both the first capacitor and the second capacitor during the second period, enabling the same switch to manage multiple capacitive elements without requiring dedicated switches for each capacitor, thus reducing overall switch complexity.
2Measurement precision
If additional components are added to achieve optimal total harmonic distortion, then conversion efficiency is improved, but device complexity increases
Solution Approach 1:
The patent combines the first capacitor and second capacitor in parallel configuration with the operational amplifier, allowing both capacitors to work together without requiring additional intermediate components. This merging strategy achieves optimal total harmonic distortion while avoiding the need for extra components that would increase device complexity.
3Measurement precision
If flicker noise modulation is implemented, then signal quality is improved, but device complexity increases due to additional switches
Solution Approach 1:
The patent implements flicker noise modulation by connecting both capacitors in parallel with the operational amplifier using a shared switch configuration. This approach achieves signal quality improvement through noise modulation while reducing the number of switches required, as the same switch structure serves multiple capacitive elements.
Solution Approach 2:
The switch configuration is designed to be universal, handling both the first capacitor and second capacitor during the second period. This multi-functional switch design enables flicker noise modulation without requiring dedicated switches for each capacitor, thereby improving signal quality while minimizing device complexity.
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
This configuration enhances the conversion efficiency by improving total harmonic distortion and signal to noise ratio, effectively modulates flicker noises into higher frequency bands for filtering, and supports both single-bit and multi-bit code processing without the need for additional switches, thereby improving overall converter performance.
Implementation Method 1
During a first period, the first capacitor stores a first voltage and the second capacitor stores a second voltage
Implementation Method 2
The switch parallels the first and the second capacitors with the operational amplifier at the input and output according to a digital signal during a second period
Data Source
AI summary
A digital to analog converter including a first capacitor, a second capacitor, an operational amplifier, and a switch is disclosed. During a first period, the first capacitor stores a first voltage and the second capacitor stores a second voltage. The operational amplifier comprises an input and an output. The switch parallels the first and the second capacitors with the operational amplifier at the input and output according to a digital signal during a second period.