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LED Driver ICs Forum Discussions

YL_Luo
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Hi,

I am evaluating TLD7002, I have questions about the interface. I see the diagram on datasheet first page, the HSLI connects directly to CANH and CANL of MCU, from my understanding, CANH and CANL will transfer CAN data format, but I don't see TLD7002 datasheet indicates it can solve CAN data format, it looks like it only can support UART data. So I have two questions:

1. does the data sheet is not right ? or my understanding is not rigfht.

2. do i need to add CAN transceiver between MCU and TLD7002, if the MCU out

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1 Solution
AliAsgar
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Hi,

Note that the data packet format from the microcontroller on UART should follow the HSLI protocol. The transceiver does just a voltage transition from single ended signals to differential signals compatible with the CAN physical layer. Hence the HSLI protocol is called "UART over CAN".

Have I answered your question correctly? If not, please let me know what have I failed to explain?

Best Regards,
AliAsgar

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AliAsgar
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750 replies posted 50 likes received 500 replies posted

Hi,

The HSLI interface of the TLD7002 is a "UART over CAN" physical layer interface. The physical layer is CAN but the protocol running on top this physical interface is that of UART. So the datasheet diagram depicts that the UART signals from the MC are sent to a CAN trasceiver to convert these UART signals such that it can be transferred on a CAN physical interface.

However, there is no necessity to use a CAN transciever. Please refer to the https://www.infineon.com/dgdl/Infineon-Infineon-Z8F80318869-TLD7002-16SHIELD-User-Guide-UserManual-v... User guide, it shows a workaround to connect UART signals directly with the HSLI interface on the TLD7002.

Best Regards,
AliAsgar

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Hi Aliasgar,

Thanks for your quick response, but I still not understand, please see my picture explanation and question.Capture.PNG 

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YL_Luo
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upload another solution, it is clearer, compare it to TLD7002 system block, it seems your system block miss a CAN transceiverCapture1.PNG

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AliAsgar
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750 replies posted 50 likes received 500 replies posted

Hi,

TLD7002 has a built in transceiver that converts the incoming differential signals from the CAN physical layer to TXD/RXD signals internally. Hence, there is no need to add another transceiver. TLD7002 can accept data from the CAN phy as it is.

Best Regards,
AliAsgar

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AliAsgar
Moderator
Moderator
Moderator
750 replies posted 50 likes received 500 replies posted

Hi,

Note that the data packet format from the microcontroller on UART should follow the HSLI protocol. The transceiver does just a voltage transition from single ended signals to differential signals compatible with the CAN physical layer. Hence the HSLI protocol is called "UART over CAN".

Have I answered your question correctly? If not, please let me know what have I failed to explain?

Best Regards,
AliAsgar

Hi AliAsgar,

Thanks for your reply. Well know the UARToverCAN. I have another question, I see the ESD level of HSLIH and HSLIL marked 8kV HBM, from my understanding, it is different with ISO10605 8kV, if my system needs to support ISO10605 8kV, do i need to add external ESD diode to pass the ESD requirement?

YL_Luo_0-1671018650334.png

Thanks, LY

 

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AliAsgar
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750 replies posted 50 likes received 500 replies posted

Hi LY,

Human Body Model (HBM) is an ESD discharge mode for component ESD susceptibility and ISO 10605 is a standard for system-level ESD with harsher voltages and rising times.

To meet the ISO 10605 standard, you can add external ESD diodes. However, please find my below comments:

1. If the capacitance of the ESD diode is not too big, there should not be any problems. For instance, I see that 30kV external protection diodes have capacitances in the range of 15pF and low leakage current. This should not have any effect on TLD7002 performance.

2. On the output pins, there are no problems too, upto 100nF capacitance is allowed.

3. The only critical pins would be the HSLI, but often 50-100pF capacitors are added, which should not cause any problems.

Also the diode in fact should act as an open load (or a small capacitance) in normal operating conditions.

Best Regards,
AliAsgar

 

Hi AliAsgar,

thanks for your reply, it is clear.

Thanks, LY

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