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.

  • Resolved

LSF0108: how to choose the vaule of the pull up resistor

Part Number: LSF0108

hi

    when i use the LSF0108  to complete the level conversion,i found that choose the pull up resistor is difficult,because,according the equation of the datasheet,the    pull up risistor =(Vpu-0.35v)/0.015A,

for the equation ,i must know the current first,but a lot of dataheet don't given this parameter,so, i can't dicide the value of the pull up resistor.

   on my schematic,please see the following diagram,at the sign 1,there is a 10k pull up resistor at the other page,and the side A(pin8),there is a 1k pull up resistor,is OK?

at the sign 2,there is a 10k pull up resistor at the other page,and the other sideA(pin9),there is a 10k pull up too,is right?

and other pins,the side B are 1.24k pull up,and side A are 1k,is OK ?

the same chip  and the different channels the pull up resistor is different,is OK?

please check it for me ,thanks.

  • Hello,

    We have a video series that talks about this that I think might help you.  The video on up-translation has the equations I use for selecting pull-up resistors at about the 4:32 mark

    I would recommend watching the whole series though - it isn't that long, and gives a ton of useful information for designing with the LSF family of translators.


    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.

  • In reply to Emrys Maier:

    thanks!

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.