What is the operating voltage of the LIN bus?
3 Answers
LIN bus voltage is 12V. The control units controlled by the LIN bus are generally distributed in relatively close proximity, and data transmission is single-wire, with the data line length reaching up to 40m. In the master node, a 1kΩ resistor is configured to terminate the 12V power supply, while in the slave nodes, a 30kΩ resistor is configured to terminate the 12V power supply. Below is relevant information about the LIN bus: 1. LIN is a low-cost serial communication network: The LIN bus is defined as a low-cost serial communication network for automotive distributed electronic systems, serving as a supplement to other automotive multiplex networks such as the Controller Area Network (CAN). It is suitable for applications that do not require high bandwidth, performance, or fault tolerance. 2. LIN is a special case of UART: The LIN bus is based on the SCI data format and adopts a single master controller/multiple slave device mode, making it a special case of UART. 3. The goal of LIN: The goal of LIN is to provide auxiliary functions for existing automotive networks, hence the LIN bus is an auxiliary bus network. 4. LIN can save costs: In scenarios where the bandwidth and multifunctionality of the CAN bus are not required, such as communication between smart sensors and braking devices, using the LIN bus can significantly reduce costs.
I've always been fascinated by automotive electronic systems, especially the LIN bus that controls functions like windows and seats. It typically operates under the car's 12-volt battery system, with a range of roughly 6 to 18 volts. Why? Because the car battery voltage is unstable and fluctuates during engine start-stop cycles. The LIN bus is designed to be flexible and can adapt to these variations. During actual communication, the signal voltage is about 5 volts, which helps reduce power consumption and costs while avoiding interference with other systems. If your car experiences LIN faults, such as door lock failures, it might be due to an aging battery causing the voltage to drop too low. I recommend regularly checking the battery's health and using a multimeter to measure the positive and negative terminals—keeping it around 12 volts ensures peace of mind. Be cautious when modifying your car; avoid adding high-voltage devices, as they can easily damage the control modules.
Last week, my car's rearview mirror stopped adjusting, and after checking, I found the LIN bus voltage was a bit low! Normally, this thing operates around 12 volts, supplied by the car battery, but during actual operation, the voltage needs to stay stable within a reasonable range, say 9 to 16 volts. Since it handles communication for small components like the air vent controller, unstable voltage can mess up signal transmission and cause functions to fail. I've dealt with similar issues before—once, a modified audio system spiked the voltage to 18 volts, frying the LIN node. In daily driving, battery problems are the most common, with aging or insufficient charging causing low voltage. Sticking to factory specifications is key; avoid randomly adding aftermarket devices. If you encounter intermittent issues, first check the battery health—replacing it or adjusting the charger can often solve the problem.
