Random-Order Multi-Channel Sampling Reduces Chip Area
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Solution Overview
Problem
Conventional multi-channel sampling methods require a large chip area due to the need for multiple comparators and anti-aliasing filters, especially in safety-critical applications like automotive systems, which increases complexity and cost.
Innovation Solution
A device and method that uses a single sampling device to sequentially sample input signals from multiple channels in a random order with additional delays, providing non-uniform sampling periods to prevent aliasing without the need for anti-aliasing filters, thereby reducing chip area requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple comparators are used to monitor multiple supply voltages, then monitoring reliability is improved, but chip area increases
Solution Approach 1:
The patent combines multiple comparator functions into a single comparator by using a multiplexer to sequentially connect different voltage rails to the same comparator. This merging approach maintains monitoring capability while significantly reducing the number of comparators needed from multiple to one, thereby reducing chip area.
Solution Approach 2:
The single comparator is designed to perform multiple functions by monitoring different voltage rails sequentially through the multiplexer. The comparator becomes a universal monitoring element that can compare any selected voltage rail against its threshold, replacing what would traditionally require separate dedicated comparators for each rail.
2Area of stationary object
If comparators are multiplexed into a single comparator, then chip area is reduced, but aliasing occurs due to uniform sampling
Solution Approach 1:
The patent introduces dynamic, random sampling intervals by using a random number generator to determine variable delay periods between successive comparisons of different voltage rails. This dynamic timing prevents uniform sampling patterns that cause aliasing, while the single comparator continues to provide area-efficient monitoring.
Solution Approach 2:
The sampling parameters are changed from fixed uniform intervals to variable random intervals. The delay period between comparisons is randomly selected from multiple possible values, transforming the sampling regime to eliminate aliasing while maintaining the area benefits of a single comparator.
3Object-generated harmful factors
If anti-aliasing filters are added to prevent aliasing, then aliasing is reduced, but chip area and device complexity increase
Solution Approach 1:
The patent extracts the anti-aliasing function from traditional analog filter circuits and implements it digitally through random sampling interval control. By removing the need for complex analog anti-aliasing filters and implementing aliasing mitigation through software-controlled random timing, the solution reduces both chip area and device complexity while effectively preventing aliasing.
Data Source
AI summary
Devices for sampling a plurality of input signals are provided, wherein a sampling device is controlled to sample the input signals in a random order with additional delays. Other embodiments relate to voltage monitoring systems and corresponding methods.