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TXB0104-Q1: Using pulled up resister for I2C

Tomoaki Yoshida91
Genius 5255 points
Part Number: TXB0104-Q1
Other Parts Discussed in Thread: TXS0102-Q1, LSF0204

Hi Team,

We would like to use TXB0104-Q1 for I2C.

I understand that TXS0102-Q1 is reccomended for I2C, but VIH and VIL of TXS0102-Q1 doesn't meet our spec.

Since we need bi-directional level shifter for I2C, 4ch products are best.

Since LSF 0108-Q1 is 8-channel product, I think that TXB 0104-Q1 is best if it can be used for I2C in a bidirectional level shifter.

I would like to judge whether TXB0104-Q1 can be used for our purpose.

It is written that any external pull up or pull down resister are recommended larger than 50k ohms in datasheet.

I think that this constraint is due to the drivability and will affect VOH and VHL.

If pull-up resister is 30k ohms, VOH and VOL will meet our spec.

If VOH, VOL satisfies the requirements in our system, can it be used with a pull-up resistor of less than 50kΩ?

Please let me know if there are other restrictions and check points.

Best regards,

Tomoaki Yoshida

  • 0
    TI__Guru 62240 points
    Tomoaki San,

    Please go through the app note regarding the effects of pullup resistors on TXS and TXB devices.
    www.ti.com/.../scea054.pdf
    If the lower pullup resistor works for the application satisfying the Voh Vol requirements of the receiver device, then you could use the device.

    For my curiosity, do you know when is the production ramp happening? What is the timeline for which you could consider using the LSF0204 commerical version now given that we can come out with the -Q1 version after confirmation?
  • 0 in reply to ShreyasRao
    Genius 5255 points
    Hi Shreyas-san,

    Thank you for your support.
    I will check whether it can satisfy the system requirement.

    Our schedule is very tight.
    Your offer is appreciated, but CS samples are needed at least in March of this year.

    Best regards,
    Tomoaki Yoshida