Automotive Electronics

CAN (Controller Area Network)

Basic Description

CAN is a hardware and software communication protocol originally developed by Robert Bosch GmbH in 1986 for in-vehicle networks in cars. CAN buses employing twisted wire pairs were specifically designed to be robust in electromagnetically noisy environments. The applications of CAN in automobiles include engine control communications, body control, and on-board diagnostics. CAN buses can also be found in other embedded control applications such as factory automation, building automation, and aerospace systems.

A CAN bus enables microcontrollers in a car to talk to each other without the need for a network host. A typical automobile today has dozens of microcontrollers that communicate with each other via various CAN buses.

Key Features
Maximum Data Rates: 1Mbps at 40m, 125Kbps at 500m, 50kbps at 1000m
Circuit Type: Differential
Physical Layer: Twisted Wire Pair, 9 pin D-Sub
Transmission Format: Asynchronous
Drive Voltage: High: 2.75v ~ 4.5v; Low: 0.5v ~ 2.25v; Differential: 1.5v ~ 3.0v
Network Topology: Point to Point
Standards: ISO 11898/11519
For More Information
[1] CAN Bus, Wikipedia.
[2] Controller Area Network (CAN) Overview, National Instruments website.