Differential ADC Noise Compensation Using Input Buffer Signals
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Solution Overview
Problem
Existing analog-to-digital converters face noise issues due to circuit non-linearity and harmonic signals when converting single-ended analog inputs to differential signals, affecting the accuracy of digital representation.
Innovation Solution
An analog-to-digital converter design that includes an input buffer generating both positive and negative differential signals and a noise compensation signal, which is used by the analog-to-digital conversion module to eliminate noise through a comparator, specifically utilizing operational amplifiers and virtual ground terminals to ensure accurate digital representation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If an input buffer is used to convert single-ended analog input to differential signals, then the conversion function is achieved, but noise is introduced due to circuit non-linearity and harmonic signals
Solution Approach 1:
The patent applies preliminary action by generating a noise compensation signal in advance from the virtual ground terminal before the noise affects the differential signals. This compensation signal is then used to pre-correct the noise in the differential output signals, allowing the ADC to achieve accurate conversion without being degraded by the input buffer's non-linearity and harmonic distortion
Solution Approach 2:
The patent introduces a noise compensation signal as an intermediary element that mediates between the noisy differential signals and the ADC conversion process. This compensation signal, derived from the virtual ground terminal, acts as a corrective intermediary that eliminates the harmful noise components introduced by the input buffer, allowing clean signal conversion
2Measurement precision
If noise compensation is implemented through virtual ground terminals, then noise elimination is achieved, but device complexity increases
Solution Approach 1:
The patent applies self-service by utilizing the virtual ground terminal's inherent noise characteristics to generate its own compensation signal. The virtual ground terminal naturally produces a signal that mirrors the noise present in the differential outputs, and this self-generated compensation signal is then used to eliminate the noise, making the system self-correcting without requiring external noise measurement or complex filtering circuits
Data Source
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AI summary
An analog-to-digital converter with noise elimination is disclosed. The analog-to-digital converter converts a single-ended analog input into digital representation, and comprises an input buffer and an analog-to-digital conversion module. The input buffer outputs a positive differential signal and a negative differential signal based on the single-ended analog input. The analog-to-digital conversion module receives the positive differential signal and the negative differential signal to generate the digital representation. The input buffer further transmits a noise compensation signal to the analog-to-digital conversion module. The noise compensation signal contains noise information about noise transmitted from the input buffer to the analog-to-digital conversion module through the positive differential signal and the negative differential signal. The analog-to-digital conversion module uses the noise compensation signal to compensate for the noise transmitted from the input buffer to the analog-to-digital conversion module through the positive differential signal and the negative differential signal.