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LSF0108-Q1: supply current

noureddine tariba
Prodigy 180 points
Part Number: LSF0108-Q1

Hello

 i need to define the supply current  of LSF0108-Q1 , this IC is powered by Vref_A= 3.3V,  and Vref_B=5V; all GPIO are pull  up with resistor  1Kohm of each side 

   i need the  Max current supply in the range  of -40°C to 115°C

 
 Best regards 

N.TARIBA 

  • 0
    TI__Mastermind 24485 points

    Hello,

    Please refer to the following app note regarding the LSF family of devices.

    http://www.ti.com/lit/an/slva675b/slva675b.pdf

    If you look at Figure 1 in the app note, you will see that the Vref_B and Vref_A supplies are connected. The way this works is that Vref_B will supply current to Vref_A. This means that there is technically no VCC to ground current, which means that ICC for the device isn't easy to specify.

    If we take the worst case, however, Vref_B can be as high as 5V and Vref_A can be as low as 0.95. Therefore, we can calculate the maximum current as the voltage difference between these two supplies, divided by the recommended 200k resistor required as shown in the figure.

    The variation will depending on the variation of the resistor value over temperature, which can be calculated further based on the resistor used.

    I hope this helps to clarify. Please let us know if you have additional questions.

    Best,
    Michael

  • 0 in reply to Michael J Schultis
    Prodigy 180 points
    Hello Michael

    I understand the concept ; thank you

    Brest regard
    N.Tariba
  • 0 in reply to noureddine tariba
    TI__Mastermind 24485 points
    Hello,

    Very happy to help. Please continue to use the forums, as we continuously monitor them to ensure questions are answered in a timely manner.

    Thank You,
    Michael