TMUX1101: SEL Pin Input Current

Part Number: TMUX1101

Context:

I have 3x1.5V (4.5V) button cells powering a 2V LDO VReg which in turn powers a PIC12. The PIC12 is capable of sourcing 25mA and will be interfacing with the SEL pin of the TMUX1101.

The TMUX's datasheet states the absolute maximum input current required by the SEL pin is 30mA, but that it has a max leakage current of 0.06uA.

The TMUX will be powered directly from the 4.5V battery pack and will be switching on a load drawing ~25mA for 3ms before switching off for at least 100ms. This pattern repeats.

The application needs to be as battery friendly as possible so the possibility that the SEL pin could sink 30mA scares me. I'm also unsure how well the batteries would handle outputting ~55mA, even for 3ms.

My questions are as follows, in order of importance:

What is the typical SEL pin input current? Is this just the leakage current (listed as 0.005uA at 5V)?

Under what conditions does the SEL pin require 30mA?

//The datasheet can be found here. The absolute maximum ratings are at the top of page four and the SEL pin characteristics at 5V are near the bottom of page five.

I'm sure I'm just failing to understand something about the datasheet. Thank you for taking the time to read this.

  • Hi Nolan,

    The SEL pin will not demand 30mA. That 30mA spec is referring to the maximum current the SEL could possibly see before being damaged. The IIL/IIH spec describes what the SEL pin will actually see in regards to current going in to that pin (think of the SEL pin having a very large input resistance). So at 5V on the SEL pin, the current that will go into that pin will be 0.005uA at room temperature. The SEL pin will never require 30mA to operate (unless possibly it is already damaged).

    Thanks!

    Bryan

  • Bryan,

    Thank you for your quick reply.

    That's what I expected, but wanted confirmation before proceeding with my design.

    God bless,

    Nolan