CAN Transceiver usage in L99DZ200G

[dlkeng]

I've recently evaluated the AEK-MOT-MR200G1 and AEK-MOT-TK200G1 evaluation boards to gain a better understanding of using the L99DZ200G device and have noticed that neither of those boards used the on-chip CAN transceiver in the L99DZ200G device but, instead, used a separate CAN transceiver device.

Is there a known problem with using the on-chip CAN transceiver in the L99DZ200G device?

Should I also use a separate CAN transceiver if I'm to use the L99DZ200G in a design?

I've written an Arduino library to control the L99DZ200G device from an Arduino Nano, Arduino Nano Every, or a Teensy 3.1 (using Teensyduino).

(see https://github.com/dlkeng/Arduino_DLK_L99DZ200G)

[Max VIZZINI · Accepted solution]

Hi DLK,

Very acute observation! 

The internal CAN transceiver is Listen mode only with the transmitter disabled.

Refer to attached datasheet paragraph 4.10.1. 

Therefore you need another external CAN transceiver if you want to carry out a standard CAN bus communication, exactly as you have seen the AEK-MOT-TK200G1 and the AEK-MOT-MR200G1.

I guess next question is: why did you put such a CAN transceiver inside the L99DZ200G?

To understand this need, you have to consider the requirements of the Automotive market. The CAN transceiver is used to program the connected microcontroller via a specific bootloader during mass production of the ECU.

It can also be used for OTA (over-the-air) updates of the same microcontroller firmware.

For this reason the CAN transceiver supports the pretended networks and it is able to wake-up the IC based on network activity.

We would like to thank you for writing the Arduino library for our device.

Best Regards,

AutoDevKit Team