> For the complete documentation index, see [llms.txt](https://nxp.gitbook.io/mr-canhubk344/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://nxp.gitbook.io/mr-canhubk344/hardware/connectors-and-user-i-o/can-buses.md).

# CAN Buses

## Location of CAN Bus Connectors

<figure><img src="/files/lJvqVj5T3gwL8NrAd9KA" alt=""><figcaption></figcaption></figure>

## CAN Connectors

There are six independent CAN FD capable CAN buses, each with two connectors. The dual connectors are only for convenience in forming a bus and or plugging in a CAN termination board.&#x20;

<table><thead><tr><th width="189">Bus Name</th><th width="139.33333333333331">CAN PHY</th><th>Type</th></tr></thead><tbody><tr><td>CAN0, CAN1</td><td>TJA1443</td><td>CAN FD</td></tr><tr><td>CAN2, CAN3</td><td>TJA1463</td><td>CAN FD, SIC (Signal Improvement CAN)</td></tr><tr><td>CAN4, CAN5</td><td>TJA1153</td><td>CAN FD, SCT (Secure CAN Transceiver)</td></tr></tbody></table>

**Connectors P12 through P23** are the CAN connectors. For each “CANx” bus connector the pinout is as follows (where x = BUS number 0 to 5):

| Pin # | Signal  | Specification |
| ----- | ------- | ------------- |
| 1     | 5V4     | 5.4V output   |
| 2     | CANx\_H | 5.0V          |
| 3     | CANx\_L | 5.0V          |
| 4     | GND     | 0V            |

Pin 1 of each CAN connector is available to supply 5V to externally connected CAN devices. This optionally may be used to supply limited power to a CAN peripheral. A blocking diode prevents powering the CANHUBK344 from the CAN BUS.

<figure><img src="/files/nzdc6rmyVjyTpUSc65bd" alt=""><figcaption><p>CAN_P5V4 power output R69 disconnect</p></figcaption></figure>

### CAN Termination

A CAN bus usually requires 60 Ohm termination at both ends of a CAN bus. This may be accomplished using one of the included CAN-TERM boards.&#x20;

Each can bus connects to TWO identical connectors labelled A and B. This is to allow for daisy chain wiring and multiple drops along a can bus. Should the MR-CANHUB344 be the end of the CAN bus and require termination, then termination may be provided by plugging in a termination board or populating (soldering) the normally unpopulated termination resistors directly on the board.

<figure><img src="/files/6BSEusbGnmdsvDcgwkww" alt=""><figcaption><p>CAN bus representative schematic</p></figcaption></figure>

### CAN SIC Termination

Note that the CAN **SIC** PHYs are able to operate with **stub** connections and potentially a single or **central termination**. The signal integrity should be validated against your specific system configuration.