TMUX1308-Q1: Sampling input overvoltage protection

Dandan LI

Part Number: TMUX1308-Q1

Use 1V8 supplied the TMUX1308-Q1.

If ADC channel input voltage over 1.8V(like 18V, not last long ), do i need add some protection parts ?
solution1: No need, connect directly
solution2: add resistor in series to limit the current and dual diode to clamp to voltage below (1.8+Vdiode)V, like picture.
Or other suggestion?

2 months ago

0 Nir Gilgur 2 months ago

TI__Mastermind 22745 points

Hello Dandan,

The TMUX1308-Q1 has short to battery protection, which is explained in the datasheet.

There is no need for external protection components other than a series resistor to limit the current.

Thanks,

Nir

0 Dandan LI 2 months ago in reply to Nir Gilgur

Prodigy 80 points

Thanks for you support.

In datasheet, the limit resistor selection affects Vout accuracy.

The example given in datasheet, 5V for VCC, 18V Vbat-> 3K. But for my design, 1V8 for VCC supply and Max 18V input for channel. I use 100K in series, how can i choose this value?

0 Nir Gilgur 2 months ago in reply to Dandan LI

TI__Mastermind 22745 points

Hello Dandan,

Yes, that is correct. With additional resistance on the line your signal integrity is negatively affected.

100k should be more than enough to protect the mux in your application.

Thanks,

Nir

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TMUX1308-Q1: Sampling input overvoltage protection