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dlkeng
Associate III
Nov 28, 2023 10:21 PM UTC
Solved

CAN Transceiver usage in L99DZ200G

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)

 

 

This topic has been closed for replies.
Max VIZZINI
Max VIZZINIBest answer
ST Technical Moderator
Nov 29, 2023 9:31 AM UTC

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. 

2023-11-29 10_09_20-Datasheet - L99DZ200G - Automotive front door device with LIN and CAN providing .png

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

 

  

 

1 reply

Max VIZZINI
Max VIZZINIBest answer
ST Technical Moderator
Nov 29, 2023 9:31 AM UTC

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. 

2023-11-29 10_09_20-Datasheet - L99DZ200G - Automotive front door device with LIN and CAN providing .png

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