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TMUX1574: Powered-off protection and I/O beyond supply

user6290036
Prodigy 250 points
Part Number: TMUX1574
Other Parts Discussed in Thread: SN74CB3Q3257, TS5A23159

We are looking for an IC that satisfies the following conditions.
I don't think TMUX1574 meets the following requirements.
Please let me know the IC that satisfies the following conditions.
・Power-off protection is 5.5V or more
・On-resistance is 5Ω or less
・ Absolute maximum rating of Vs(VD) is 6V or more
・Can be driven by power supply voltage 2.5V
【How to use IC】
Using the signal from A as a trigger, 18 signals from A and 18 signals from B are switched and output to C
  • 0
    TI__Expert 5660 points

    Hello,

    Welcome to E2E.

    TMUX1574 fits most of these requirements:

    • Ron less than 5Ω
    • Abs max of VS, VD = 6V
    • Supports supply voltage of 2.5V

    TMUX1574 supports powered-off protection for VS, VD signals up to 3.6V when VDD < 1.5V.

    SN74CB3Q3257 fits the above requirements with the addition of powered-off protection for Vi/o up to 5.5V.

    To clarify, do you need to pass I/O signals up to 6V with a supply of 2.5V? In other words, is input beyond supply a necessary feature?

    In addition, is a 4-channel 2:1 mux configuration required? Could you try re-sending the image attachment?

    Thanks!
    Kate

  • 0
    TI__Expert 4120 points

    Hi,

    I found the TS5A23159 2ch 2:1 MUX. 

    • It is powerd-off protected up to 5.5V (max. leakage current 20 μA)
    • Ron 0.7 Ω
    • Vs up to Vcc+ 0.5V
    • VCC range: 0 - 5.5V

    Let us know if you have more questions on our devices.

    Best regards,

    Ambroise

  • 0 in reply to Kate Dickson
    Prodigy 250 points
    Thank you for your reply.
    I will answer below.
    >TMUX1574 supports powered-off protection for VS, VD signals up to 3.6V when VDD < 1.5V.
    The fact that the power-off protection of Vs and VD is up to 3.6V means that if a voltage of 5V is applied, the operation of the IC is not guaranteed, right?
    >To clarify, do you need to pass I/O signals up to 6V with a supply of 2.5V? In other words, is input beyond supply a necessary feature?
    Yes.I want to use it to switch A or B signal as shown below
    1362.Figure.pptx
  • 0 in reply to Ambroise Suter
    Prodigy 250 points

    Thank you for your reply.

    Let me check one point.

    If the maximum absolute rating of the signal line (VNC, VNO) is "Vcc + 0.5" V, does that mean there is no power-off protection?

    Because if Vcc = 0, the maximum absolute rating would be 0.5V, right?
  • 0 in reply to user6290036
    TI__Expert 4120 points

    Hi,

    This is in fact a bit confusing, I found an older thread that explains this a bit further:

    Essentially, the max ratings are for normal operation, although we recommend to use the part within the recommended operating conditions.


    Best regards,

    Ambroise

  • 0 in reply to Ambroise Suter
    Prodigy 250 points
    Please tell me 3 points.
    〇Question1
    In the case of TS5A23159, I understand that it is recommended to use it while power is supplied.
    So what happens when 5.5V is applied to the signal line with VDD = 0V?
    〇Question2
    Please tell me about IC with Isolation in Power-Down Mode like TS5A23159.
    Is the operation of the IC guaranteed even if 5.5V is applied to Vs or VD when VDD = 0V, and then VDD is turned on?
    〇Question3
    As shown below, if A and B are powered on but C is not powered, 5.5V will be applied to the signal line even though Vcc is not supplied to the IC.
    After the above, please let me know the IC that can operate normally when the power of C is turned on.

    6574.Figure.pptx

  • 0 in reply to user6290036
    TI__Expert 4120 points

    Hi,

    to your questions:

    1. If Vs is 5.5V and VDD is 0V, the output will be close to 0. Only a small leakage current of up to 20μA will appear on the drain pin (COM)
    2. Yes, the operation of the IC is guaranteed in this setting. The IC will turn on once VDD is >= VS (5.5V in this case)
    3. If the switch is powered on and you apply a 5.5V signal, subsystem C might be damaged, depending on its ratings.

    For more information, check our video on Powered-Off Protection and our Appnote on the same subject.

    Best regards,

    Ambroise

  • 0 in reply to Ambroise Suter
    Prodigy 250 points

    Thank you fot your reply.


    I'm sorry, I misunderstood.
    When using TS5A23159, I understand that VDD should be smaller than VS and VD.
    Therefore, use SN74CB3Q3257.


    Sorry, please tell me additionally.

    ①I want to know the ON resistance (Ron) when the SN74CB3Q3257 is used at VDD = 2.5V and VS (VD) = 3.3 to 5.5V.
    Do you have a graph that shows the relationship between VDD, VS, and Ron?

    ②Is there an order to apply voltage to OE, S, VDD terminal?

     ③Please let me know for reference.
    Is there an IC other than the SN74CBT3257C that operates at VDD = 5V instead of VDD = 2.5V in the same case as this question?
    I hope that 2.5V received from C will be boosted to 5V and used to increase IC options.

  • 0 in reply to user6290036
    TI__Expert 4120 points

    Hi, you are welcome!

    1. check out this thread: CB3Q3257 Ron. The images are quite small but you can see, that Ron stays below the Ron,max from the datasheet.
    2. We recommend to apply VDD first, OE and S don't matter. 
    3. The SN74CBT3257C should run with VDD=5V perfectly fine, as it's recommended range is 4-5.5V.

    Best regards,

    Ambroise

  • 0 in reply to Ambroise Suter
    Prodigy 250 points

    Thank you for your reply.


    1.I saw this page, please tell me.If VI is applied at 2.5V or more with VDD = 2.3V, Ron becomes very large. Is this the same when VDD = 2.5V?

    If so,does that mean that if Vcc = 2.5V and VI = 5.5V, Ron becomes too large and the signal is attenuated, making it useless?

    2.I understand that it is recommended to apply OE, S, and VI after supplying VDD.
    However, since power down protection is provided, there is no problem if 5V is applied to OE and S with Vcc = 0V, right?

    3.I see.Thank you.

  • 0 in reply to user6290036
    TI__Expert 4120 points

    Hello,

    1. As these older devices use NMOS switches, Ron will increase exponentially as Vgs (Gate-Source) becomes smaller or even negative.
      For more information please have a look at our Precision lab video on switch architecture: Switch Architectures
    2. These older devices don't have Fail-Safe Logic. The moment you turn on VDD there will be a high current from OE into VDD as power down protection does not apply to the logic pins. You could limit the current on the OE pin with a resistor to the maximum current in the datasheet.
      Otherwise we recommend to have OE low before turning on VDD. For more information on Fail-Safe logic, watch this video: Fail-Safe Logic

     Thank you and best regards,

    Ambroise

  • 0 in reply to Ambroise Suter
    Prodigy 250 points

    Thank you for your reply.

    1.Since the gate voltage is Vcc + 2 to 3 V, I understand that the switch will turn ON even if VIN is larger than Vcc.
    However, from the graph below, if V is increased when Vcc = 2.3 V, Ron appears to diverge,
    At Vcc = 2.5V and VIN = 5V, I am afraid that Ron is too large to use.
    What I want to know in the end is what is the value of Ron when Vcc = 2.5V and VIN = 5V?

    2.I will connect OE directly to GND so that it is always low.

  • 0 in reply to user6290036
    TI__Genius 9132 points

    Hi User,

    Looks like you have similar questions on the following thread.

    I will close this thread and we can use the other thread to answer your questions.

    Thanks

    Saminah