• TI Thinks Resolved

LSF0108: The voltage of port A will be pulled up to about 2.5V.

Part Number: LSF0108

The following is the hardware circuit diagram of lsf0108, VrefA is 1.8V, VrefB is 3.3V.

The current phenomenon is: A port voltage will be pulled to about 2.5V.           

Our application is 1.8V Master, which communicates bidirectionally through SPI interface and 3.3V Spare. The SPI rate is 25 Mhz.           

Can the lsf0108 support the above requirements and is there any error in the hardware circuit? If there is a more suitable IC, please also trouble to provide models.

  • Hi Allen,
    I would highly recommend watching the video series for the LSF family of translators on the Logic Minute, located here: training.ti.com/LogicMinute

    This series goes into a great deal of detail on how the part works, and should help to clear up any issues you are having. If you still are having trouble after that, please let me know and I will do my best to help.

    Also, your image did not post -- I see the same thing that you do.

    Looking for a low voltage translator? Check out the AXC family that supports 0.7V to 3.3V translation!

    The Logic Minute training page has videos on many interesting topics that all are kept shorter than 5 minutes.