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SN74AUC2G53: SN74AUC2G53 Vcc

user5182412
Prodigy 90 points
Part Number: SN74AUC2G53
Other Parts Discussed in Thread: TMUX1219, SN74LVC1G3157, SN74CBT3257

Hi, Team,

We are considering using SN74AUC2G53 in a 3.3V system. As the recommended Vcc is 2.7V max , but the Absolute Maximum Ratings is limited to 3.6V, how about apply the 3.3V Vcc and control inputs for long term reliable working?

Best Regards,

James

  • 0
    Guru 297930 points

    As long as you stay below the absolute maximum ratings, the device will not be damaged or degraded.

    But if you exceed the recommended operating conditions, the electrical characteristics are no longer guaranteed.

    Why don't you use a 3.3 V switch like the SN74LVC1G3157 or TMUX1219?

  • 0
    TI__Genius 10974 points

    Hi James,

    While it is not advised to utilize our devices outside the recommended operating range, as long as you do not exceed the absolute maximum ratings this can be done. However, we do not guarantee any of our datasheet specifications for this range and would not be able to predict any performance metrics at this operating level.

    If you need 3.3V operation, it would be a good idea to use a multiplexer that can support this in its recommended operating range such as the ones mentioned by Clemens.

    Thanks!

    Bryan

  • 0 in reply to Bryan Marshall
    Prodigy 90 points

    Hi, Clemens & Bryan,

    Many Thanks!

    The reason for the  74AUC2G53 is for the higher switching speed and bandwidth. It seems the fastest deivce in the analog switching group and the Ron will improve when Vcc is 3.3V. What would be the main risk when apply the 3.3V Vcc?

    Best Regards,

    James 

  • 0 in reply to user5182412
    TI__Genius 10974 points

    Hi James,

    The risk with this is that it leaves almost no headroom for fluctuations in the supply. If there are any events that move the supply more than 10% (not uncommon), you risk permanently damaging the device. In addition, there is no data on how the device performs parametrically, so it will be on the customer to evaluate any parametrics at this operating level.

    The SN74LVC1G3157 has marginally lower bandwidth (340MHz vs 500MHz) and very similar RON performance while being able to operate at the 3.3V voltage range with no risk. I would highly suggest using this part for your application unless you truly need 500MHz.

    Thanks,

    Bryan

  • 0 in reply to Bryan Marshall
    Prodigy 90 points

    Hi, Bryan,

    Many Thanks again!

    1. We will add a 3.3V LDO for this part only, to  protect it from over voltage shock.

    2. We tested the  SN74LVC1G3157 before but found higher current consumption and heating when switching at around 100Mhz. So considering the more faster one. We will test it as your kindly advice!  

    3. Does 74AUC2G53 the fatest switching one in your analog switching catalog?

    4. Is there any more information for the AUC series part ? Why they are more faster than the LVC part? So interestiong to know about.

    Best Regards,

    James 

  • 0 in reply to user5182412
    TI__Genius 10974 points

    Hi James,

    For our 2:1, 1 channel muxes, this would be the fastest we have available. However, if you can use a 2:1, 2 channel mux, we have some that are much faster (just GND the input/output channel you are not using). Some examples include the TMUX154E, TMUX136, and TMUX1072.

    For further reading, we do have the "AUC Data Book" which goes into a bit more detail on this series:

    https://www.ti.com/lit/ug/sced011a/sced011a.pdf?ts=1625158923060&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FSN74AUC2G53

    Thanks!

    Bryan

  • 0 in reply to Bryan Marshall
    Prodigy 90 points

    Hi, Bryan,

    Many Thanks for your kindly help!

    I have read the parts you advised and the signal bandwidth are the faster but the switching time are far slower than the 74AUC2G53, which reach the 2.2ns limit.  We are more concerned about the Ton / Toff time than the bandwidth.  It seems the 74AUC2G53 is the fatest in the catalog at the point of view?

    Best Regards,

    James 

  • 0 in reply to user5182412
    TI__Genius 10974 points

    Hi James,

    What is this application where you need such switching speeds? Also, what is the actual requirement besides being "fast"? We offer many parts that probably could meet your use case, but would need more information on what that would be. SN74AUC2G53 is definitely a good choice in terms of good TON/TOFF performance if you are needing only a 2:1 switch with bandwidth of over 500MHz.

    Thanks,

    Bryan

  • 0 in reply to Bryan Marshall
    Prodigy 90 points

    Hi, Bryan,

    Many Thanks !

    We use the switch in a sampling detector, where the RF signal charge a small cap through the switch. So the TON/TOFF would be the most critical and then the bandwidth and Ron. The two or four 2:1 switch in one package is also acceptable.

    Would like to have your advice!

    Best Regards,

    James 

  • +1 in reply to user5182412
    TI__Genius 10974 points

    Hi James,

    For that range of switches, the SN74AUC2G53 has the best TON/TOFF performance (2.2ns max) for its operating range of up to 2.7V. However, I want to make sure you understand that it will not be possible for us to guarantee those specifications at the voltage you want to use it at. Another comparable device with a bit lower bandwidth (300MHz) and slightly higher TON/TOFF (8ns max), but can operate at your required voltage level would be the SN74LVC2G53.

    Hope this helps.

    Thanks!

    Bryan

  • 0 in reply to Bryan Marshall
    Prodigy 90 points

    Hi, Bryan,

    Many Thanks !

    Further more, I notice the information on your Little Logic Guide , page 4 , the Performance Comparisons table, it tell the AUC support 3.6V Input Tolerance. That is to say, I can supply with the 2.7V Vcc and the CONTROL INPUTS still keep the 3.3V rail?  If so , that might be a riskless solution.

    Best Regards,

    James

  • +1 in reply to user5182412
    TI__Genius 10974 points

    Hi James,

    You are correct. If you can supply 2.7V for VCC (note, can only pass input voltages up to VCC) and 3.3V for your control inputs (recommended up to 3.6V), this is within the recommended operating conditions of the device.

    Thanks!

    Bryan

  • 0 in reply to Bryan Marshall
    Prodigy 90 points

    Hi, Bryan,

    Many Thanks !

    We will try.

    Best Regards,

    James

  • 0 in reply to Bryan Marshall
    Prodigy 90 points

    Hi, Bryan,

    Further more, I notice there have a bus switch sn74CBT3257 ,which have the similar function to the SN74LVC1G3157 in the analog switch application. Both of them also have similar Ron and Ton/Toff when Vcc=5V. What would be the advantage and disadvantage for the bus switch comparing to the analog switch?

    Would like to have your advice!

    Best Regards,

    James

  • 0 in reply to user5182412
    Guru 297930 points

    The CBT was designed for TTL signals, so it runs only at 5 V, and cannot pass voltages near 5 V.

  • 0 in reply to user5182412
    TI__Genius 10974 points

    Hi James,

    They will perform similarly. I would not expect their to be significant differences or advantages between the two devices in your use case.. The biggest difference is the amount of channels you have available between these two devices. I believe the SN74AUC2G53 is the best device for your application.

    Thanks,

    Bryan

  • 0 in reply to Clemens Ladisch
    Prodigy 90 points

    Hi, Clemens ,

    Many Thanks!

    How about the Vin MAX=3.3V when supply the CBT with 5V? 

    Best Regards,

    James 

  • 0 in reply to Bryan Marshall
    Prodigy 90 points

    Hi, Bryan,

    Many Thanks !

    I got it!

    Best Regards,

    James

  • 0 in reply to user5182412
    TI__Genius 10974 points

    Hi James,

    You can view this thread for more explanation of this family of devices (CBT):

    https://e2e.ti.com/support/switches-multiplexers-group/switches-multiplexers/f/switches-multiplexers-forum/898824/sn74cbt3257-is-this-device-can-used-for-3-3v-spi-signal

    As long as the input signal is not near VCC, it will perform as expected.

    Thanks,

    Bryan

  • 0 in reply to Bryan Marshall
    Prodigy 90 points

    Hi, Bryan,

    Great help! Thanks a lot!

    Best Regards,

    James