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Connecting common output of analog switch together


 I want to know what will happen if i connect common output of the 4X SPDT analog switch together to use it as a 4:1 MUX? I want such configuration because i want low Ron resistance with low cost. The multiplexer available with low ON resistance are not fitting in our cost. We require component with cost lest than 0.3USD|1KU AND Ron less that 10ohm. So looking for some good solution.

can i use TS3A44159 part as 4:1 Mux with connecting COM out  together ? How it will affect the system. 


  • Vidula,

    There isn't any issue cascading signal switches together to make 4:1 function out of 3x 2:1 switches.  However when you cascade the switches you will have 2x the parasitic elements of a FET switch like on-state resistance, capacitance, etc.


    I searched your requirements on the TI.com switch selection tool.  I used the filters on the left hand side for 4:1 configuration, <10 Ohm Ron, and <$0.30 1ku price which returned 3 results (SN74CBT3253C, SN74CBT3252, and SN74CBTLV3253).  Do these not meet your requirements?


    Thank you,


  • In reply to Adam Torma:


     Thank you very much for your efforts.SN74CBTLV3253 can be used the only issue is it has max 40ohm Ron resistance which may cause offset in our readings. I found another part i.e.TS5A3359 which is 3:1 analog switch which i think i can use. Actually i was unaware of SP3T (3:1) type switches that's why i asked for 4:1 configuration.

    Thank you TI for always helping us.:-)

  • In reply to vidula badhe:


    I'm sorry I didn't fully understand your Ron requirement that it need to be <10 ohms at 85 deg. I didn't know your application operated at this temperature. I'm glad you were able to find better suited 3:1 switch for your application.

    Thank you,