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ADG5206/1206 current consumption and rise times


Hi,

I'm planning on designing in the ADG5206/1206 for a low power, low leakage measurement application. The digital inputs to the ADG5206 or ADG1206 (still balancing power consumption / leakage requirements) are isolated, so ideally I could output slow rise time signals (~1-3us). Is this a problem for these switches? Should I expect significant glitching with one or both of these analog switches with such slow rise times? The switch is going to be powered at +/-15V (or 30V single supply, depending on digital requirements or the answer to this question)

Additionally, I noticed that the ADG1206 has a very different I/O structure than the ADG5206, and consumes a huge amount of current when the digital inputs aren't GND or VDD. If I use a 5V logic voltage (with +/-15V) or 15V logic voltage (with +30V/0V supply), will the ADG5206 have a similar issue?

Basically, I'm trying to design a battery powered, fully isolated switch system switching moderately high voltage (<30V) signals, and it is going to be difficult to replace the batteries, so I'm trying to keep all the leakage currents very low throughout the system (including regulators, etc.)

Thanks!

Sam

  • Hello Sam,

    Thanks for your questions.

    I do not foresee any issues (glitching or otherwise) with the 1-3us rise times that you are describing.

    It sounds like the ADG5206 will be a better fit for your application.

    The reason the ADG1206 consumes more current when the logic levels are below VDD is explained in this article:

    How do CMOS switch logic control voltage levels affect Idd?

    The ADG5206 however has an internal VL generator that is used to power the input buffer at a lower voltage so you can use a lower digital logic voltage without significantly impacting IDD.

    One other thing to note is that the max single supply voltage for ADG1206 is 16.5 V. You can use this part for +-15 V but not for 30 V single supply. The ADG5206 can be used for both, up to 40 V single supply and +-22 V dual supply.

    One more article that might be of interest to you is this one

    Switch & Multiplexer Leakage Measurement Reduction Tutorial

    It outlines methods to  layout PCB traces to ensure the accuracy of low current leakage switches and multiplexers.

    Regards,

    David