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SN74LVCH16T245 current consumption

SM
Expert 1730 points

 Hello,

          In our board FPGA I/O lines are connected to the inputs of the 245 and the I/O voltage is set to 2.5V. The FPGA is not configured so I presume the interface pins between the FPGA and 245 must be tri-stated. The 245 might either be pulling up its inputs (inputs are at VREFA of 2.5V). The device is consuming a lot of  current  and getting heated up (up to 2.5W). Please advise. 

Port A is referenced to 2.5V and Port B to 5V. The level translation is from A to B.

  • 0
    TI__Expert 6335 points
    SM,

    Sorry for the delayed response. I was on vacation.

    1. I would suggest that you double check if the FPGA really does tri-state the pins instead of assuming.
    2. Do you have a schematic that you can share with us?

    Best Regards,
    Nirav
  • 0 in reply to Nirav Patel
    Expert 1730 points

    Nirav,

           Thank you for your reply.

    1) I got it confirmed today. The outputs of the FPGA are tri-stated. 

    2) I'll try to get the schematic. 

    Regards,

    SM>

  • 0 in reply to SM
    Expert 1730 points

    Nirav,

     An observation:

    If OE is disconnected from GND and the inputs are not tri-state then the current consumption becomes normal.
    & 
    If OE is connected to GND and inputs are not tri-state then the current consumption is high.