SLLSFE8B November 2024 – November 2025 TCAN2845-Q1 , TCAN2847-Q1
PRODUCTION DATA
The ISO 11898-2:2024 Standard specifies a maximum bus length of 40m 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 large number of nodes requires transceivers with high input impedance such as the TCAN284x-Q1. Many CAN organizations and standards have scaled the use of CAN for applications outside the original ISO 11898-2:2024. These organizations have made system-level trade-offs for data rate, cable length, and parasitic loading of the bus. The device is specified to meet the 1.5V requirement with a 50Ω load, incorporating the worst case including parallel transceivers. The differential input resistance of the device is a minimum of 30kΩ. If 100 of the devices are in parallel on a bus, this is equivalent to a 300Ω differential load worst case. That transceiver load of 300Ω in parallel with the 60Ω gives an equivalent loading of 50Ω. Therefore, the TCAN284x-Q1 theoretically supports up to 100 transceivers on a single bus segment. However, for CAN network design margin must be given for signal loss across the system and cabling, parasitic loadings, network imbalances, ground offsets and signal integrity thus a practical maximum number of nodes is typically much lower. Bus length can also be extended beyond the original ISO 11898-2:2024 standard of 40m 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 11898-2:2024 CAN standard. In using this flexibility comes the responsibility of good network design and balancing these tradeoffs.