Receiving Module Threshold Switching for Serial Bus Signal Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current serial bus systems, such as CAN FD, face challenges in reliably detecting bus signals across different communication phases, particularly with the physical layer switching between phases, which affects error rates and bit transfer rates.
Innovation Solution
A receiving module with multiple voltage dividers and comparators that set different reception thresholds, allowing switching between these thresholds based on the communication phase, enabling reliable detection of bus signals and maintaining high bit rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single reception threshold is used for all communication phases, then the device complexity is reduced, but the reliability of signal detection deteriorates when switching between communication phases with different physical layers
Solution Approach 1:
The receiving module dynamically switches between different reception thresholds based on the current communication phase. A switching unit selects between a first reception threshold for the first communication phase and a second reception threshold for the second communication phase, allowing the system to adapt to different physical layer requirements while maintaining reliable signal detection
Solution Approach 2:
The receiving module is segmented into multiple independent threshold-setting paths. Each voltage divider is configured to generate a specific reception threshold for a particular communication phase, allowing parallel evaluation of differential signals against multiple thresholds without requiring a single complex adaptive threshold mechanism
2Measurement precision
If different reception thresholds are used for different communication phases, then the measurement precision of bus signals is improved, but the device complexity increases due to multiple voltage dividers and comparators
Solution Approach 1:
The measurement function is segmented into multiple independent comparator units, each dedicated to evaluating differential signals against a specific reception threshold. The first comparator evaluates signals against the first threshold while the second comparator evaluates against the second threshold, allowing precise measurement for each communication phase without requiring a single complex adaptive measurement system
Solution Approach 2:
Multiple voltage dividers are configured to generate different reception thresholds from the same differential signal input. Each voltage divider-comparator pair serves a specific communication phase requirement, but all components work together within a single receiving module, providing multi-functional capability without requiring completely separate measurement systems for each phase
3Productivity
If the physical layer switches between two communication phases, then the productivity of data transmission is increased, but the reliability of communication deteriorates due to potential detection errors during phase transitions
Solution Approach 1:
The receiving module prepares both reception thresholds in advance, with the switching unit pre-configured to select the appropriate threshold based on the current communication phase. This preliminary preparation of threshold options eliminates detection errors during phase transitions, as the correct threshold is already available when the phase changes occur
Solution Approach 2:
The receiving module uses feedback from the communication phase identification to control the switching unit. The switching unit monitors which communication phase is active and automatically selects the corresponding reception threshold, creating a closed-loop system that adapts to phase changes and maintains reliable detection across different transmission rates
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
A receiver module (122) and a method for transmitting differential signals in a serial bus system (1) are provided. The receiver module (122) has a first voltage divider (1531) for setting a first receive threshold (T1), a first comparator (151) connected to the first voltage divider (1531) for evaluating differential signals (CAN_H, CAN_L) received from a bus (40) of the bus system (1) with the first receive threshold (T1), a second voltage divider (1532) for setting a second receive threshold (T2) or a third receive threshold (T3), and a second comparator (152) connected to the second voltage divider (1532) for evaluating the differential signals (CAN_H, CAN_L) received from the bus (40) with the second or third receive threshold (T2, T3) set by the second voltage divider (1532).and a switching unit (1533) for switching between the second and third receive thresholds (T2, T3) depending on an operating mode of the receive module (122), into which the receive module (122) is to be switched for a first or second communication phase (451, 452) of a communication on the bus (40), wherein the first and second voltage dividers (1531, 1532) are each connected to the bus (40).