TMUX1104: TMUX1104 for measuring low quiescent current

Part Number: TMUX1104
Other Parts Discussed in Thread: TMUX1108

Hello TI Member:

I would like to use TMUX1104 as a programmable circuit to measure the current consumption, and the order of quiescent current is about 10nA.

Since the leakage current of the component (TMUX1108) will affect the measurement accuracy, so we choose the low leakage current version, TMUX1104.

Do you think TMUX1104 is suitable for this application?

By the way, could you also recommend some product which can pass clock frequency about 200MHz with 1 : 8 safely? 

Thank you!

B.R

Chen

  • Hi Chen,

    The TMUX1104 could work in this application. A few questions:

    1) What precision do you need for this measurement? The typical leakage current is around 3pA at 25C, so this would lead to very minimal accuracy discrepancy.

    2) Will you be running this over temperature at all? If so, the 125C spec for leakage can increase to 2nA which may be unacceptable for you.

    For your second question, what is the voltage of the signal you are passing? We certainly have muxes that can pass 200MHz, but the amplitude of the signal will be the determining factor in which mux I can recommend.

    Thanks!
    Bryan

  • Hello Bryan:

    Thank you for your kindly reply.

    My requirement is listed below:

    1) The accuracy is tens of pA (1E-11)

    2) Yes, the temperature is from -40C to 125C, so the leakage current at 125C may be an issue

    3) The maximum voltage amplitude is 1.21V

    Thank you!

    B.R

    Chen

  • Hi Chen,

    The best you could do then is to use 2x TMUX6122 (1:1x2 switch) in parallel and mux your inputs that way. This would lead to the lowest case leakage across temperature (still would be around 1 nA though). We do not have a part that could provide tens of pA's of precision over temperature.

    For the 8:1 mux for 200MHz and 1.2V, I would recommend the TMUX1308. Should meet all your needs!

    Thanks!

    Bryan