• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 18 subscribers
  • Views 262 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TXS0206: and TXS0206-029

Dan
Prodigy 30 points
Part Number: TXS0206
Other Parts Discussed in Thread: SN74AXC2T45

Hi,

I actually have several questions about the TXS0206 and TXS0206-029. I am new to SD interfaces and after checking the support threads I didn't really find what I was looking for.

  1. In both devices, how is direction control handled?
    1. Does the device snoop on the traffic protocol and change direction automatically?
  2. What is the difference between the TXS0206 Vccb and the TXS0206-029 Vccb O/P?
    1. They are both fed VccB, so what is the O/P representing?
      1. Does this just mean Output?
  3. It appears that TXS0206 WP and CD as well as TXS0206-029 WP/CD pins in the Figure 1 SD Card reference designs are connected to both the Vcca and Vccb power domains.
    1. What is going on here vs what should go on here?
    2. Should WP and CD be at Vcca or Vccb?
    3. If they should be at Vcca then are the TXS0206 and TXS0206-029 WP, CD, and WP/CD pins operating in the Vcca power domain?
  4. The TXS0206-029 indicates in the terminal functions table on page 3 that WP/CD is only connected to the WP pin at the SD card connector.
    1. But, the reference design in Fig. 1 on page 2 shows that WP/CD is also connected is to the CD pin at the SD card connector.
      1. Which is correct, the reference design or the table?
  5. For the TXS0206-029 how does the WP/CD shared pin function?
    1. They are separate pins in the TXS0206 and some other devices I've seen.
  6. Just to be clear, the TXS0206-029 LDO is fixed at 2.9V so this would not be suitable for an SD card requiring 1.8V - correct?
  7. Will the TXS0206 support SD UHS-I Speed Class 10?
    1. Would you suggest a different device/family to support SD UHS-I Speed Class 10?

Thank you!

   

  • +1
    TI__Mastermind 27798 points

    Hey Dan,


    Dan said:
    In both devices, how is direction control handled?

    These are auto-direction-sensing devices. See page 18 of the TXU0206-029 datasheet

    Dan said:
    What is the difference between the TXS0206 Vccb and the TXS0206-029 Vccb O/P?

    Yes the O/P stands for output. This is where the '-029' comes from in the naming of the device.

    Dan said:
    It appears that TXS0206 WP and CD as well as TXS0206-029 WP/CD pins in the Figure 1 SD Card reference designs are connected to both the Vcca and Vccb power domains.

    WP and CD are for write protection and card detection. They are internally pulled up to VCCA so if the associated pins on the processor and SD card connector are left floating they'll have a known high state rather than an unknown floating state. 

    Dan said:
    The TXS0206-029 indicates in the terminal functions table on page 3 that WP/CD is only connected to the WP pin at the SD card connector.
    Dan said:
    Which is correct, the reference design or the table?

    I would say they're both correct but the design is more correct. But I see how not having the CD mentioned in the description seems incomplete. The WP/CD can be used for both. It's simply a 100k ohm pull up resistor to Vcca. If you choose to integrate it, you can use it for just the WP or both. 

    Dan said:
    For the TXS0206-029 how does the WP/CD shared pin function?
    1. They are separate pins in the TXS0206 and some other devices I've seen.

    This is covered in my last answer but i'll repeat here. This is just a pullup resistor. The current would just be split if you're using the WP/CD pin for two inputs. The left is the 029, the right is the TXS0206

        

    Dan said:
    Just to be clear, the TXS0206-029 LDO is fixed at 2.9V so this would not be suitable for an SD card requiring 1.8V - correct?

    That is correct. This device was made specifically for memory cards operating at 2.9V

     

    Dan said:
    Will the TXS0206 support SD UHS-I Speed Class 10?
    1. Would you suggest a different device/family to support SD UHS-I Speed Class 10?

    I'm not terribly certain on what you mean here. My understanding is that UHS-1 denotes roughly 100MBps and a clock frequency of 100Mhz, while Speed class 10 denotes 10MBps which I believe would also have a clock of 10MHz. My knowledge on the technically details of this are a bit limited so correct me if i'm wrong in this. In which case though, for UHS-1 the TXS would probably not be able to handle this. I would recommend the integrated something like the SN74AXC2T45 or any other family of AXC devices. They can support up to 190MHz.


    Thanks,
    Rami