Delta-Sigma ADC Multiplexer Array for VCO Bit Shift Mitigation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional continuous time ΔΣ ADCs experience bit shifting due to the use of VCO phase quantizers, which affects the performance and accuracy of digital-to-analog converters (DACs).
Innovation Solution
A continuous time ΔΣ analog-to-digital converter with a mitigation bit shifting multiplex array is introduced, featuring a loop filter, a VCO responsive to analog signals, a multi-stage phase quantizer, and a multiplexer array that shifts selected misaligned bits of the quantized phase difference value to mitigate bit shifting. The multiplexer array is coupled to the multi-stage phase quantizer and adjusts the output by a predetermined amount of bits, specifically half the number of stages rounded up, to correct for bit alignment issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a VCO based quantizer is used instead of a conventional quantizer, then power consumption is reduced, but bit shifting occurs in the digital output affecting DAC performance and accuracy
Solution Approach 1:
A multiplexer array is introduced as an intermediary component between the VCO phase quantizer and the DACs. This multiplexer array detects bit shifting in the digital output and performs corrective bit shifting to realign the most significant bit, thereby maintaining digital output accuracy while preserving the power consumption benefits of the VCO based quantizer.
Solution Approach 2:
The system implements a feedback mechanism where the digital output from the VCO phase quantizer is monitored for bit shifting conditions. When bit shifting is detected, the multiplexer array applies corrective action by shifting bits in the opposite direction to compensate for the misalignment, ensuring the digital output remains accurate for DAC operation.
2Power
If a multi-stage VCO phase quantizer is used, then power consumption is reduced compared to conventional quantizers, but bit shifting affects DAC performance and accuracy
Solution Approach 1:
The multiplexer array serves as a mediator that sits between the multi-stage VCO phase quantizer and the DACs. It monitors the digital output for bit shifting and applies corrective shifting to ensure the most significant bit is properly aligned, thereby protecting DAC performance and reliability while allowing the power-efficient VCO quantizer to operate.
Solution Approach 2:
The invention converts the harmful effect of bit shifting into a beneficial correction process. By detecting bit shifting patterns and applying compensatory bit shifting through the multiplexer array, the system transforms the original problem into a controlled correction mechanism that actually improves overall system reliability.
3Measurement precision
If conventional quantizers are used, then digital output accuracy is maintained, but power consumption increases significantly
Solution Approach 1:
The quantization function is segmented into two parts: the power-efficient VCO phase quantizer handles the bulk of the quantization, while a separate multiplexer array handles only the bit shifting correction. This segmentation allows the system to benefit from the low power consumption of the VCO quantizer while adding minimal overhead for maintaining digital output accuracy.
Solution Approach 2:
The system changes the operational parameters of the quantizer by using a VCO based approach instead of a conventional clocked quantizer. This parameter change dramatically reduces power consumption, and the multiplexer array compensates for the resulting bit shifting issue, achieving both low power consumption and maintained accuracy.
4Use of energy by moving object
If a VCO phase quantizer is used, then power consumption is reduced, but bit shifting requires additional correction circuitry
Solution Approach 1:
The correction functionality is segmented into a dedicated multiplexer array that is separate from the VCO phase quantizer. This segmentation allows the complex correction logic to be isolated and optimized independently, adding minimal complexity to the overall system while maintaining the power efficiency of the VCO quantizer.
Solution Approach 2:
The multiplexer array performs multiple functions: it routes the digital output from the VCO phase quantizer, detects bit shifting conditions, and applies corrective bit shifting when needed. This multi-functionality consolidates several operations into a single component, reducing overall device complexity despite the added correction capability.
Data Source
AI summary
A continuous time ΔΣ analog-to-digital converter with mitigation bit shifting multiplex array including a loop filter, a VCO responsive to analog signal configured to adjust the output frequency based on the magnitude of the analog signal and produce a digital output, a multi-stage phase quantizer responsive to the digital output configured to determine the phase of the VCO by comparing the phase of the VCO for a particular sample to a reference phase at said particular sample and generate a quantized phase difference value, and a multiplexer array coupled to the multi-stage phase quantizer configured to shift selected misaligned bits of the quantized phase difference value by a predetermined amount of bits to mitigate bit shifting of the multi-stage phase quantizer.