TMUX6219: something about TMUX6219

Henry_Wu

Part Number: TMUX6219

Tool/software:

I have two questions regarding the MUX chip.

First, which MUX chip should I select? My analog input signals are either ±10V at 0-30kHz or 0-20mA at 0-30kHz. Therefore, I need a MUX to switch between these input signals. Is the TMUX6219 an appropriate choice?

Second, do I need an isolator between the TMUX6219 and the MCU? As you know, I intend to use the MCU's GPIO pins to control the TMUX6219's SEL pin.

4 months ago

0 Clemens Ladisch 4 months ago

Guru 280910 points

Here is a search for one-channel, 1:2 MUXes that support ±10 V supplies and low-voltage control signals: ti.com/switches-multiplexers/analog/products.html#480=1&1143=2:1 SPDT&2192=1.8-V compatible control inputs&3307=+/-10

The TMUX6219 is a good choice.

0 Henry_Wu 4 months ago in reply to Clemens Ladisch

Prodigy 160 points

Thank you for your response. Regarding the second question, what would be your recommendation?

0 Clemens Ladisch 4 months ago in reply to Henry_Wu

Guru 280910 points

You do not need an isolator.

0 Alex Vish 4 months ago

TI__Genius 10552 points

Hi Henry,

Clemens gave good feedback here with the link to various switches that fit your criteria. I also tend to agree that you do not need an isolator in this case. Using MCU GPIO pins to control the TMUX control pins is a very common use case that does not require an isolator.

Regards,

Alex

0 Henry_Wu 4 months ago in reply to Alex Vish

Prodigy 160 points

Hi Alex and Clemens

The IO reference ground of MCU is the digital ground and the reference ground of MUX is the analog ground. Is it reasonable that IO will cross the digital ground and the analog ground? Or what do you suggest?

Henry

0 Clemens Ladisch 4 months ago in reply to Henry_Wu

Guru 280910 points

Current spikes can happen only during switching. And I assume you have proper decoupling capacitors.

0 Henry_Wu 4 months ago in reply to Clemens Ladisch

Prodigy 160 points

You mean IO could have a decoupling capacitors?

0 Clemens Ladisch 4 months ago in reply to Henry_Wu

Guru 280910 points

There should be decoupling capacitors between V_DD/V_SS and GND.

0 Henry_Wu 4 months ago in reply to Clemens Ladisch

Prodigy 160 points

I see. Anyway, it doesn't need isolator. Thank you very much

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TMUX6219: something about TMUX6219