ADC Gain and Resolution Adjustment for Quantization Noise Control
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Solution Overview
Problem
Analog-to-digital converters (ADCs) face challenges in maintaining signal-to-noise ratio (SNR) when processing high-amplitude analog signals, as existing technologies fail to effectively adjust gain and resolution in real-time to compensate for increased signal amplitudes, leading to increased quantization noise.
Innovation Solution
The implementation of an analog-to-digital conversion circuitry with an adjustable sample capacitor and multiplier, which decreases capacitance and resolution in real-time to compensate for increased signal amplitudes, maintaining SNR by adjusting the attenuation factor and using a shift register to multiply the output, thereby adapting gain and resolution dynamically.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the ADC processes high-amplitude analog signals with fixed gain and resolution, then the circuit structure remains simple, but the signal-to-noise ratio deteriorates due to increased quantization noise
Solution Approach 1:
The patent implements dynamic adjustment of the sample capacitor capacitance value based on the amplitude of the input signal. The capacitor value is changed in real-time to match the signal amplitude, allowing the ADC to maintain optimal signal-to-noise ratio across varying signal levels. This dynamic adaptation resolves the contradiction by making the circuit parameters variable rather than fixed.
Solution Approach 2:
The patent changes the capacitance parameter of the sample capacitor according to the input signal amplitude. By adjusting this key parameter dynamically, the system maintains consistent signal-to-noise ratio performance whether processing low-amplitude or high-amplitude signals, thereby resolving the contradiction between maintaining reliability and managing device complexity.
2Object-generated harmful factors
If the ADC uses fixed resolution, then the circuit complexity remains low, but quantization noise increases when processing high-amplitude signals
Solution Approach 1:
The patent dynamically adjusts the resolution of the ADC by changing the sample capacitor value in real-time based on signal amplitude. This dynamic resolution adjustment reduces quantization noise for high-amplitude signals while maintaining circuit feasibility, resolving the contradiction between reducing harmful factors and managing device complexity.
Solution Approach 2:
The system incorporates feedback mechanisms that monitor the input signal amplitude and adjust the capacitor value accordingly. This feedback loop enables the ADC to automatically adapt its resolution to match the signal characteristics, minimizing quantization noise while maintaining manageable circuit complexity through automated control.
3Reliability
If the gain is increased to accommodate high-amplitude signals, then the full-scale range is utilized, but the signal-to-noise ratio deteriorates due to quantization noise
Solution Approach 1:
The patent makes the gain characteristic dynamic by adjusting the sample capacitor value based on signal amplitude. This allows the system to maintain optimal signal-to-noise ratio across a wide range of signal amplitudes, resolving the contradiction between maintaining reliability and achieving adaptability to different signal levels.
Solution Approach 2:
The patent creates a universal ADC circuit that can handle both low-amplitude and high-amplitude signals effectively by dynamically adjusting the capacitor value. This multi-functional capability allows the same circuit to maintain high signal-to-noise ratio performance across varying signal conditions, resolving the contradiction between reliability and adaptability.
Data Source
AI summary
Analog-to-digital conversion circuitry for generating a digital output signal is disclosed comprising a sample-and-hold circuit comprising an adjustable sample capacitor for coupling to an analog input signal during a sample phase, and an analog-to-digital converter (ADC) coupled to an output of the sample-and-hold circuit during a hold phase. In order to compensate in real-time for an increase in an amplitude of the input signal, a capacitance of the sample capacitor is decreased by an attenuation factor, and an output of the ADC is multiplied by an inverse of the attenuation factor to generate the digital output signal.