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TMUX6208: Testing

Chris C
Prodigy 10 points
Part Number: TMUX6208

Tool/software:

I'm currently testing TMUX6208 on a breadboard and have connected the TMUX6208 chip with the following 5V and GND shown in the figure below. 

I want to be able to measure the 5V (given on the D pin) on whichever selected Switch using a multimeter. I tested first on Switch 1 (S1), but I'm able to measure the 5V on all pin S1,S2,S3,S4 even though I should only be able to measure the 5V on S1. Is there something wrong in my setup or do I have to add something for the chip to work. 

 

  • 0
    TI__Mastermind 35638 points

    Hey Chris,

    Interesting that you're seeing that. That isn't what I would expect. How are you connecting it to the breadboard? Wondering if there's a short.
    Have you replaced the device with a new one? Could be an isolated incident. Make sure you're handling the device with care and use an ESD strap. 
    Since the setup looks fine, let's start with an A-B swap and putting a new unit on and seeing if the issue follows first. 

    Thanks,
    Rami 

  • 0
    Guru 317370 points

    Disconnected Sx pins have a high impedance, i.e., they do not have any voltage. The measured value might be an artifact of the multimeter's measurement.

    Did you check continuity with the D pin, or with VDD/GND? (Please note that there are clamping diodes to VDD/GND.)

  • 0 in reply to Clemens Ladisch
    Prodigy 10 points

    I measured the Sx pins to the D pin and that was around 50k ohms using the multimeter. How do I test the Low on-resistance 4ohms that is listed on the data sheet? Can I use a multimeter or should I use a impedance spectroscopy?

  • 0 in reply to Rami Mooti1
    Prodigy 10 points

    I tried swapping the Chip with a new one, but same result. I used a soldering iron at 350C and an ESD strap. I soldered it on a PCB like below and that PCB board has header pins which sit on the breadboard. The wiring on the breaboard is the same as before. 

  • 0 in reply to Chris C
    TI__Mastermind 24440 points

    Hello Chris,

    From what I have gathered after reading everything I think what is happening is  because the other pins are floating and  you are measuring with a multi-meter, you will see 5V even on the unselected channels. This because even on the off channels the Impedance of the multimeter is so much larger than the off resistance of the mux that you will see 5V on the unselected channels.

    Could you try to put  pull down resistors on the  s pins and see if that helps?

    Please let me know if this helps!

    regards,

    kameron