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TMUX1119: Muxes power consumption

Part Number: TMUX1119
Other Parts Discussed in Thread: TS5A9411

Hi,

I got a question on power consumption of  muxes like TS5A9411, TMUX1119 when active.

Static power consumption stated in datasheet is low, but what is the right figure for total/active power consumption?

Thanks

Saminah

  • Hey Saminah,

    Good question. Sound like your trying to pick between the two. What's the use case for these? 

    So this answer depends on your operating conditions.

    To begin the power supply level would need to be known. The TMUX1119 can operate from 1.08V to 5.5V. On the higher end you'll see supply currents at 1uA max. On the lower end when operating at 1.2Vcc it's listed at 0.7uA max. The typical of these is well below (~3nA) but i'm going to list the worst case scenarios here.
    You can find this information in the Electrical Characteristics section of the datasheet. Here's an example for the TS5A9411 with a 2.75V power supply:





    You'll notice here that the logic levels are at VCC or GND in the Test Conditions. This is because the logic level impacts the supply as well. Typically we recommend using the device with logic levels on the low and far ends of your logic levels. The closer your logic voltages lie to the gray inbetween area (0.8-1.35 below) the worst this generally is for the power consumption as the switch will leak more current from the power supply. For example, we'll take the TMUX1119 and look at the max Vih and min Vil levels:



    So to minimize the power consumption here, when driving the switch high you'd ideally want to use a 5.5V source and driving low to GND. You can find a table of the logic level vs supply current in some datasheets but the shape will typically be similar. Here's the TMUX1119:





    Furthermore, the voltage actually being passed through the channel will be a consumed power and can be calculated using the Ron and the voltage of the signal being passed. You can follow this forum post to gain a better understanding of this:


    So you'll see that the power consumption isn't going to be something with a readily uniformed answer. We're disregard any affects from temperature for now, but if your operating above 80C you may see a noticeable difference that may need to be taken into account.

    What would be the power supply here and logic level? This would be a good place to try and approximate this using the information provided in the datasheet. 

    Thanks,
    Rami Mooti