Noise-Shaping SAR ADC with Multi-Input Residue Amplifier
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Solution Overview
Problem
Existing SAR ADCs face challenges in achieving high signal-to-noise ratio and efficient noise shaping, leading to increased circuit area and power consumption.
Innovation Solution
The integration of a multi-input amplifier and comparator with a noise shaping loop that amplifies residue values before sampling, using capacitors to reduce noise contribution and implement a noise transfer function through gain selection and timing, allowing for reduced circuit size and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If noise shaping techniques are incorporated into SAR ADCs to improve signal-to-noise ratio, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent combines the residue amplifier and comparator into a single integrated circuit block, merging two previously separate functional units. This integration reduces the overall number of components, simplifies interconnections, and lowers device complexity while maintaining the noise shaping functionality that improves signal-to-noise ratio.
Solution Approach 2:
The integrated circuit performs multiple functions: it amplifies the residue signal, compares the amplified residue with reference voltages, and generates comparison outputs. By making the circuit multi-functional, the patent reduces the need for separate dedicated amplifier and comparator circuits, thereby reducing device complexity while preserving measurement precision.
2Measurement precision
If noise shaping techniques are incorporated into SAR ADCs to improve signal-to-noise ratio, then measurement precision is improved, but power consumption increases
Solution Approach 1:
By merging the amplifier and comparator into a single integrated unit, the patent eliminates redundant circuitry and shared components. This consolidation reduces the total power consumption while maintaining the noise shaping effect that improves measurement precision.
Solution Approach 2:
The integrated circuit recovers and reuses the amplified residue signal for comparison operations without requiring separate amplification stages. This efficient signal reuse reduces unnecessary power consumption while preserving the measurement precision benefits of noise shaping.
3Measurement precision
If noise shaping techniques are incorporated into SAR ADCs to improve signal-to-noise ratio, then measurement precision is improved, but circuit area increases
Solution Approach 1:
The patent integrates the amplifier and comparator functions into a single compact circuit block, significantly reducing the total circuit area occupied by these functional units. This area reduction is achieved by sharing common components and eliminating redundant interconnections, while the noise shaping functionality that improves measurement precision is fully preserved.
Data Source
AI summary
In accordance with an embodiment, a noise shaping successive approximation analog-to-digital converter (ADC) includes: a digital-to-analog converter (DAC); a multi-input comparator with a first input coupled to the DAC; a multi-input amplifier having a first input coupled to the DAC, and a second input coupled to a second input of the multi-input comparator; and a first delay element having an input coupled to an output of the multi-input amplifier and an output coupled to the second input of the multi-input amplifier and to the second input of the multi-input comparator.