A typical CAN application may have a maximum bus length of 40 meters and maximum stub length of 0.3m. However, with careful design, users can have longer cables, longer stub lengths, and many more nodes to a bus. A high number of nodes requires a transceiver with high input impedance such as the TCAN6062-Q1. Additionally, since TCAN6062(V)-Q1 has SIC and FAST TX, in a given network size, higher data rate can be achieved because signal ringing is attenuated.

CAN XL is intended for use in point-to-point or multi-point networks that require higher data throughput than what can be achieved by CAN FD or Ethernet 10BASE-T systems. This higher-speed connection can be used in zonal architectures to connect other lower-speed networks together without the need to translate CAN traffic to another protocol. Zonal systems can use a combination of CAN FD, Ethernet, and CAN XL to achieve high reliability connectivity across a large number of devices.

Many CAN organizations and standards have scaled the use of CAN for applications outside the original ISO 11898-2 standard. They made system level trade off decisions for data rate, cable length, and parasitic loading of the bus. Examples of these CAN systems level specifications are ARINC 825, CANopen, DeviceNet, SAE J2284, SAE J1939, and NMEA 2000.

A CAN network system design is a series of tradeoffs. In the ISO 11898-2:2024 Annex A specification, the driver differential output is specified with a bus load that can range from 45Ω to 65Ω where the differential output must be greater than 1.5V. This bus load range is extended to 45Ω by Annex A, which contains additional transceiver design specifications targeted toward CAN XL applications. The TCAN6062-Q1 family is specified to meet the 1.5V requirement down to 45Ω. This widened driver capability allows use cases with 50Ω termination, such as Cat5 or coaxial cable applications.

The differential input resistance of the TCAN6062-Q1 is a minimum of 40kΩ. If 100 TCAN6062-Q1 transceivers are in parallel on a bus, this is equivalent to a 400Ω differential load in parallel with the nominal 60Ω bus termination which gives a total bus load of approximately 52Ω. Therefore, the TCAN6062-Q1 family theoretically supports over 100 transceivers on a single bus segment. However, for a CAN network design margin must be given for signal loss across the system and cabling, parasitic loadings, timing, network imbalances, ground offsets and signal integrity; therefore, a practical maximum number of nodes is often lower. Bus length may also be extended beyond 40 meters by careful system design and data rate tradeoffs. For example, CANopen network design guidelines allow the network to be up to 1km with changes in the termination resistance, cabling, less than 64 nodes and significantly lowered data rate.

This flexibility in CAN network design is one of the key strengths of the various extensions and additional standards that have been built on the original ISO 11898-2 CAN standard. However, when using this flexibility the CAN network system designer must take the responsibility of good network design for robust network operation.

Figure 8-3 Typical CAN XL Bus

Figure 8-4 Typical CAN FD Bus with CAN SIC and CAN XL Transceivers