Bus Transceiver Biasing for Dominant-to-Recessive Oscillation Damping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In bus systems, particularly in CAN bus systems, there is a tendency for oscillation during transitions from dominant to recessive bit states, leading to increased bit times and reduced transmission rates due to insufficient damping, which can result in incorrect state recognition by transceivers.
Innovation Solution
A transceiver with an oscillation reduction unit that connects at least one bus wire to a bus bias potential when detecting a change from a dominant to a recessive state, utilizing a detection block and transistors to control the phase position of signals and reduce oscillation duration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the transition from dominant to recessive state is allowed to oscillate naturally, then the system maintains simple transceiver design, but the oscillation causes insufficient damping leading to longer bit times and reduced transmission rates
Solution Approach 1:
The patent introduces a bus bias potential as an intermediary element that mediates the transition between dominant and recessive states. This bias potential acts as a damping mechanism that reduces oscillation without requiring complex transceiver circuitry, thereby increasing transmission rate while maintaining relatively simple device design
Solution Approach 2:
The patent changes the electrical parameter of the bus system by introducing a specific bus bias potential level. This parameter change modifies the voltage characteristics during state transitions, providing natural damping of oscillations and enabling faster bit times without compromising signal integrity
2Reliability
If the bit time is extended to allow sufficient oscillation damping, then the transceiver can reliably recognize bit states, but the transmission rate is reduced
Solution Approach 1:
The bus bias potential serves as a mediator that accelerates the damping of oscillations during state transitions. This allows the system to maintain reliable bit state recognition with shorter bit times, thereby supporting higher transmission rates without sacrificing reliability
3Power
If the transceiver drives the bus with low resistance to create dominant state, then the dominant state is established, but the transition to recessive state exhibits oscillation tendency
Solution Approach 1:
The patent modifies the electrical parameters of the bus system by establishing a specific bus bias potential. This parameter change allows the transceiver to maintain strong dominant state driving capability while the bias potential provides damping during transitions, improving transition stability without reducing driving power
Data Source
Figure 1
Figure 2
Figure 3A~5B
AI summary
The invention relates to a transceiver (12; 120; 1200) for a bus system (1) and to a method for reducing an oscillation inclination upon transitioning between different bit states. The transceiver (12; 120) has a receiving comparator (1221) for receiving a signal which is transmitted from a bus (40) of the bus system (1), wherein an exclusive collision-free access of a participant station (10, 20, 30) to the bus (40) of the bus system (1) is at least temporarily ensured in the bus system (1), and an oscillation reduction unit (15; 150), the input of which is parallel to the input of the receiving comparator (1221). The oscillation reduction unit (15; 150) is designed to connect at least one bus wire (41; 42) of the bus (40) to a bus biasing potential if a state change of the received signal from a dominant bus state (402) to a recessive bus state (401) is detected.