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SN65HVD234: SN65HVD234QDRQ1

Manjunath G14
Expert 2075 points
Part Number: SN65HVD234

Hi,

I have designed a product using CAN Transceiver SN65HVD234QDRQ1, So please review the attached design  to avoid any design related issues.

  • 0
    TI__Guru 70432 points
    Manjunath,

    As far as component choice and signal wiring, this schematic looks fine, as long as you always want it in Normal mode. Tying Rs to ground keeps the device in high speed mode, and not allowing EN to go low keeps the device out of sleep mode.

    Also, what kind of common-mode choke are you using, and why are your CANH and CANL lines intersecting before said choke?

    Regards,
  • 0 in reply to Eric Hackett
    Expert 2075 points

    Hi Eric,

    Thanks for your quick response,

    Understood the functionality and configurations of RS pin and EN pin,

    Regarding Common mode choke selection: I found the spec of the choke in one of the document. Please check this also, I have mentioned P/N of the choke in the design and also please check the resistor and capacitors value.

    I have updated the schematic and I'm attaching the same now,

    Please check it and let me know if We can move further.

    Thanks 

  • 0 in reply to Manjunath G14
    TI__Guru 70432 points

    Manjunath,

    The resistance and capacitor values are good, though how many nodes are you expecting on the CAN bus? This will affect the value of C29 and C30. Also, be careful about the CANH and CANL net names, you have them swapped currently.

    I've never used that choke or a choke with that low of inductance, so I can't speak on its performance, but typically a choke with a value of 51uH or 100uH is used, like the ACT45B-510-2P-TL003. Looking at parameters in the respective datasheets, the biggest difference (besides inductance value) is the DC resistance, maximum DC current, and impedance vs. frequency.

    The 744235900 is limited to 200mA DC current max, which is more than suitable for typical CAN activity, but in a bus fault case, the current could be higher and damage the choke.

    The lower DC resistance of the 744235900 compared to the ACT45B-510-2P-TL003 (50mOhms vs. 1Ohm) will help a bit with power dissipation and leakage current on the bus.

    And the impedance at a given frequency for the ACT45B-510-2P-TL003 relative to the 744235900 is 100x more in most cases, which means with the ACT45B device, you are going to have more noise rejection. 

    So the trade-off will be based on perceived noise in the application environment, and how much power and thus current is expected to be needed for the application. As I said, it's typical for the ACT devices to be used in the automotive applications I've worked on.

    Regards,

  • 0 in reply to Eric Hackett
    Prodigy 10 points

    Thank You so much Eric for your valuable review comments,

    I have updated all your comments.

    Thanks

    Manjunath

  • 0 in reply to Anirudh Nayak K97
    TI__Guru 70432 points
    Manjunath,

    It is my pleasure to help out, please let me know if you have any other questions, and if you can, click the resolved button under my replies. This helps with our forum management system.

    Regards,
  • 0 in reply to Eric Hackett
    Expert 2075 points
    Hi Eric,
    Common mode choke ACT45B-510-2P-TL003 you have suggested is non stock in mouser, I found a alternate part DLW43SH510XK2L, Please check this part and please confirm the same.
  • 0 in reply to Manjunath G14
    Expert 2075 points

    Hi Eric,

    Please update on the common mode choke part no.

    Thanks

    Manjunath 

    Design Engineer

  • 0 in reply to Manjunath G14
    TI__Guru 62920 points
    Hi Manjunath,

    Eric is traveling internationally at the moment, so he may need a little extra time to respond.

    Max
  • 0 in reply to Miguel Robertson
    TI__Guru 70432 points

    Manjunath,

    Thank you for being patient. The alternative device you found will work. 

    Please let me know if you have any other questions.

    Regards,

  • 0 in reply to Eric Hackett
    Expert 2075 points
    Hi Eric,
    Thanks for all your valuable comments on this part,

    Manjunath

    Design Engineer