Lidar Readout Module Segmentation for Cost Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Increasing the number of receive channels in lidar systems to improve angular resolution increases the cost and complexity of the readout module due to the need for high-performance analog-to-digital converters for both timing and intensity information.
Innovation Solution
Implementing a low-cost readout module with two separate paths: a timing readout path using a threshold-triggered timing circuit with a time-to-digital converter for time-sensitive data and an intensity readout path with a hold-and-sample circuit using a low-performance analog-to-digital converter for non-time-sensitive data, allowing for shared converters across multiple intensity readout paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high-performance analog-to-digital converters are used for both timing and intensity information in each receive channel, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The readout module is segmented into two independent readout paths: a timing readout path that uses a time-to-digital converter for time-sensitive information, and an intensity readout path that uses a hold-and-sample circuit with a lower-performance analog-to-digital converter for non-time-sensitive information. This segmentation allows each path to use appropriately optimized components, reducing overall system complexity while maintaining measurement precision for both timing and intensity measurements.
Solution Approach 2:
Different components with different performance characteristics are assigned to different readout paths based on their specific requirements. The timing path uses a time-to-digital converter optimized for temporal resolution, while the intensity path uses a hold-and-sample circuit with a lower-cost analog-to-digital converter optimized for amplitude measurement. This local quality differentiation reduces device complexity while preserving measurement precision where needed.
2Measurement precision
If high-performance analog-to-digital converters are used for both timing and intensity information, then measurement precision is improved, but cost increases
Solution Approach 1:
The readout module is divided into two separate readout paths with different converter requirements. The timing path uses a time-to-digital converter, while the intensity path uses a hold-and-sample circuit with a lower-performance analog-to-digital converter. This segmentation enables the system to achieve measurement precision for both timing and intensity while using less expensive components overall, reducing manufacturing cost.
Solution Approach 2:
The patent employs a lower-performance, lower-cost analog-to-digital converter in the intensity readout path, accepting that this converter operates at a slower sampling rate with smaller bandwidth. This trade-off is acceptable because the hold-and-sample circuit compensates by holding the signal during the conversion process, and the converter only needs to capture amplitude information rather than precise timing data, thereby reducing cost while maintaining sufficient measurement precision.
3Measurement precision
If a high-performance analog-to-digital converter is used for each receive channel, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The readout module is segmented into two independent paths: timing readout using a time-to-digital converter and intensity readout using a hold-and-sample circuit with a lower-performance analog-to-digital converter. This segmentation reduces device complexity by avoiding the need for high-performance converters in both paths, while still achieving measurement precision through the specialized functionality of each path.
Solution Approach 2:
The hold-and-sample circuit in the intensity readout path serves multiple functions: it holds the signal during conversion, enables the use of a lower-performance analog-to-digital converter, and maintains measurement precision for amplitude data. This multi-functionality reduces overall device complexity while preserving measurement capabilities.
4Measurement precision
If the number of receive channels is increased to improve angular resolution, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
Each receive channel is served by two separate readout paths with different converter types optimized for their specific functions. This segmentation allows the system to support multiple receive channels for improved angular resolution while controlling device complexity through the use of appropriately optimized, rather than uniformly high-performance, converters.
Data Source
AI summary
Techniques and apparatuses are described that implement a low-cost readout module for a lidar system. The low-cost readout module includes a timing readout path and an intensity readout path, which are coupled to a receive channel of the lidar system. The timing readout path generates time-sensitive information using a threshold-triggered timing circuit, which can include a time-to-digital converter. The intensity readout path generates non-time-sensitive information using a hold-and-sample circuit, which can include a hold circuit and an analog-to-digital converter. By utilizing the threshold-triggered timing circuit to provide time-sensitive data and the hold-and-sample circuit to provide non-time-sensitive information, the readout module can have a lower cost than other readout modules that utilize a high-performance analog-to-digital converter for each receive channel.