TMUX1208: Unused pins of TMUX1208PWR

HARI T O1

Expert 1215 points

Part Number: TMUX1208

Dear Team,

I am using TMUX1208PWR in one of my applications.

I am using only inputs S1 and S2.

Other input pins are left floating. May I know this is fine or do I need to connect unused inputs to GND?

Regards

HARI

over 1 year ago

0 Rami Mooti1 over 1 year ago

TI__Mastermind 23833 points

HARI,

If you're using a high speed application then tying them to ground through a 50ohm would be recommended. Otherwise, floating is fine.
Please see :

(5) [FAQ] What to do with Unused Pins & Exposed Thermal Pads? - Switches & multiplexers forum - Switches & multiplexers - TI E2E support forums

Thanks,
Rami

0 HARI T O1 over 1 year ago in reply to Rami Mooti1

Expert 1215 points

Hi Rami,

Thank you.

I am running below 50khz.

Regards

HAri

0 Rami Mooti1 over 1 year ago in reply to HARI T O1

TI__Mastermind 23833 points

This is definitely slow enough to leave floating and not expect to see an issue from the crosstalk.

Thanks,
Rami

0 HARI T O1 over 1 year ago in reply to Rami Mooti1

Expert 1215 points

May I know at what frequency onwards crosstalk can appear.

Any thumb rule for calculating the frequency where I need to consider XTALK

+1 Rami Mooti1 over 1 year ago in reply to HARI T O1

TI__Mastermind 23833 points

HARI,

Crosstalk is spec'ed in the datasheet already at 1MHz and 10MHz. When you take xtalk into consideration just depends on your system and you should always have some consideration. For the device you've selected the crosstalk isn't spec'ed in it's fullest since it's a lower frequency device. For higher bandwidth devices we typically have frequency vs xtalk plots.
That being said you would also take xtalk in consideration with your routing. You can find some xtalk calculators online that may be helpful for this.

Thanks,
Rami