• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 16 subscribers
  • Views 332 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TMUX1308-Q1: May I connect the control pins A0-A2 of two devices in parallel to toggle them at the same time and save the number of GPIO needed?

Adam Torma
Mastermind 45575 points
Part Number: TMUX1308-Q1

E2E, 

I'm using 2x TMUX1308-Q1 in my system. 

I want to know if I can connect the control pins A0-A2 of the two devices in parallel so that my MCU only needs 3 GPIO to control both muxes at the sames time.  I have weak pull downs on the bus to avoid floating nodes but do I need to have a series resistor on each pin A0-A2 as well?

Also to save GPIO can I tie the EN pin directly to ground and have the device always enabled or do I need a weak pull down resistor as well? 

Thank you,

Adam

  • 0
    TI__Guru 52462 points

    Hi Adam,

    1.  You should be okay to connect the select lines in parallel to reduce the amount of datalines. The weak pulldown's are recommended so that there is always a defined state on the select pins. The tradeoff of using the same select lines for multiple muxes, is that the effective capacitance increases with every additional MUX, which could slow down the switching of the select lines. There is no need to add series resistors.


    2. Yes you can directly tie enable to ground to have continuous operation. 

    Best Regards,

    Parker Dodson