What voltage is CAN bus?

CAN bus is a popular communication protocol used in automotive and industrial applications. It allows different electronic control units (ECUs) to communicate with each other over a single pair of wires, thereby reducing the amount of wiring needed in a vehicle or industrial system.

The voltage used in a CAN bus system is typically 0-5 volts. However, this voltage range may vary depending on the specific implementation and requirements of the system. The standard for CAN bus communication, known as CAN 2.0, specifies that dominant bits are represented by a recessive voltage level greater than 0.9 volts, while recessive bits are represented by a dominant voltage level less than 0.6 volts.

The exact voltage levels used in a CAN bus system are determined by the physical layer transceiver (PHY). The PHY is responsible for converting digital data into electrical signals that can be transmitted over the CAN bus wires. Different transceivers may have slightly different voltage thresholds for dominant and recessive bits, but they must adhere to the specifications set by the CAN 2.0 standard.

In addition to voltage levels, the PHY also handles other aspects of signal transmission, such as bit timing and error detection. This ensures reliable communication between ECUs even in noisy environments. The use of differential signaling helps minimize the impact of electromagnetic interference on the CAN bus signals, further enhancing the reliability of the system.

It's important to note that the voltage used in a CAN bus system is not directly related to the power supply voltage of the ECUs. The power supply voltage may vary depending on the specific application and requirements of the system, but it does not affect the voltage levels used for CAN bus communication.

CAN bus systems are designed to be robust and reliable, allowing for seamless communication between ECUs in a wide range of applications. The use of standardized voltage levels helps ensure compatibility between different manufacturers and systems, making CAN bus an industry-standard protocol for automotive and industrial communications.

In conclusion, the voltage used in a CAN bus system is typically 0-5 volts, with dominant bits represented by a recessive voltage level greater than 0.9 volts and recessive bits represented by a dominant voltage level less than 0.6 volts. The exact voltage levels are determined by the physical layer transceiver, which converts digital data into electrical signals. The use of differential signaling and standardized voltage levels ensures reliable communication between electronic control units in automotive and industrial applications.