TMUX1209: high current draw with -2V / 0V referenced logic, analog at -2V / +3V

Part Number: TMUX1209
Other Parts Discussed in Thread: TMUX1204,

Hi all

My customer has preselected the TMUX1209 and the TMUX1204 because of the 1.8V logic compatible control inputs.

In their system the uC supply is -2V / 0V while the analog supply for the multiplexers is -2V / +3V.

In this setup they find a current-draw of 200uA for the multiplexers, this is way too much for their limited power budget.

Is this behavior expected ?

Controlling the MUX between -2V and +3V doesn't show this increase in current draw.

Best regards

Ueli

over 3 years ago

+1 Bryan Marshall over 3 years ago

TI__Genius 10974 points

Hi Ueli,

The TMUX1209/1204 are single, positive supply devices only, so if you are trying to apply a negative supply voltage for these devices, that will not work.

Can you clarify exactly how they are wiring up the mux they are using and the exact input voltages for each pin?

Thanks!

Bryan

0 Ue over 3 years ago in reply to Bryan Marshall

TI__Genius 16285 points

Hi Bryan

Thank you for the quick reply, I will follow-up by EMail to explain the details of the application.

Best regards

Ueli

0 Ue over 3 years ago

TI__Genius 16285 points

Hi Bryan

Referring to our EMail exchange:

Thank you for pointing to this application note providing more detailed information on the behavior:

Application Brief 1.8 V Logic for Muxes and Signal Switches (scaa126a):

https://www.ti.com/lit/an/scaa126a/scaa126a.pdf?ts=1618005233408

Best regards

Ueli

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TMUX1209: high current draw with -2V / 0V referenced logic, analog at -2V / +3V