TS12A12511: Internal circuit required for the pinout

Jason Fan

Part Number: TS12A12511
Other Parts Discussed in Thread: TMUX1072

Hi Experts:

Can I know the relative internal circuit of the pinout of COM, NC, IN, NO because my customer want to know the behavior of the scenario below ?

a) input 12V on the COM pin , and float the V+ , what's the voltage on the V+ ?

b) is it potential risk in the case of a) ?

over 6 years ago

0 Adam Torma over 6 years ago

TI__Mastermind 45410 points

Jason,

If you float V+ pin and place a voltage on the I/O pins you will violate the abs max ratings stated in the datasheet.

a) if you place 12V on COM pin and float V+ the voltage on the V+ pin will likely be the voltage on the COM pin minus a diode drop from the internal esd protection diode. This can cause a couple issues with the device including backpowering the switch causing the COM pin to connect to the NC pins and drive current into the V+ node potentially back powering or damaging other components in the system.

What are you trying to achieve in your system? Maybe there is a better suited device that has backpower protection. What do you think about the TMUX1072?

Thank you,

Adam

0 Jason Fan over 6 years ago in reply to Adam Torma

TI__Intellectual 1705 points

Hi Adam:

Thanks for your explanation. I know it should be problem caused by the internal pull up ESD diode.

It's better that you can provide me the rough internal circuit and i can give customer visual explanation .

i will promote the TMUX1072 to customer if they do need to power on the Com pin at first.

0 Adam Torma over 6 years ago in reply to Jason Fan

TI__Mastermind 45410 points

Jason,

Here is an image from the application note System-Level Protection for High-Voltage Analog Multiplexers.

Let me know if this is what you are looking for.

Thank you,

Adam

0 Jason Fan over 6 years ago in reply to Adam Torma

TI__Intellectual 1705 points

Hi Adam:

Thanks for your information .

The TMUX1072 can't be used in customer system because the range of the signal should be 0V to +10V which TMUX can't support.

As I know , the switcher should have the power-off protection to resolve this issue by the chipset level , however, all the switcher with this function could handle the 5.5V for the maximum input signal . So is there any device I can choose for this issue ?

If not, how can we resolve this issue by the hardware configuration such as adding some protection circuit?

0 Adam Torma over 6 years ago in reply to Jason Fan

TI__Mastermind 45410 points

Jason,

TI currently doesn't have a 1-channel 2:1 device that will support 10V and has powered off protection. You could follow the protection mentioned in the app note above starting on page 4 using a series resistor and zener diode on the supply pin.

What are you connecting to the switch in your system that needs 0 to 10V?

Thank you,
Adam

0 Jason Fan over 6 years ago in reply to Adam Torma

TI__Intellectual 1705 points

Hi Adam:

Thanks for your reply, I can't see the attached app note , could you please resend again.

The product is the AC inverter ,the 0 ~10V is very popular signal range of the AC inverter for the analog output /input to transfer the control signal.

0 Adam Torma over 6 years ago in reply to Jason Fan

TI__Mastermind 45410 points

Jason,

Here is the link to the appnote System-Level Protection for High-Voltage Analog Multiplexers.

Thank you,

Adam

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TS12A12511: Internal circuit required for the pinout