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Help deciphering ts5a23159 power off state

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oliv3r:
Hey all.

I'm trying trying to understand what the [TS5a23159](http://www.ti.com/lit/ds/symlink/ts5a23159.pdf) does when no voltage is present on VCC (VCC < 0.1).

The datasheet has only one image really talking about the 'PWROFF' state, Figure 15 (attached). Which somehow ironically seems to imply that when VCC is 0, we get NO closed, and NC open?!

What I'm after, is that I want to know what the default state of the switch is without power applied, or if it always needs power to function. If this where a relais the answer would be obvious, but this being solid-state territory; I don't know.

I currently toggle the power to this switch and some other control logic via a mosfet, and while the consumption is probably irrelevant, I do want to know if I should keep the switch always powered.

xvr:
Datasheet paragraph 10 (Power Supply Recommendations):

--- Quote ---Always sequence VCC on first, followed by NO, NC, or COM.
--- End quote ---

Also, all Electrical Characteristics tables contains row:

--- Quote ---COM, Vno, Vnc: Analog signal range: 0 - VCC
--- End quote ---

So when Vcc is 0 all input/output should be zero.

--- Quote ---What I'm after, is that I want to know what the default state of the switch is without power applied, or if it always needs power to function.
--- End quote ---
Default state doesn't matter - output always will be 0

As I can guess this chip (as any other CMSO) has protection diodes to power rails on input/output, so when you turn off power (to high Z state) it will power itself from all NC/NO inputs (or COM, if it will be used as input)

oliv3r:

--- Quote from: xvr on July 18, 2024, 01:41:33 pm ---Datasheet paragraph 10 (Power Supply Recommendations):

--- Quote ---Always sequence VCC on first, followed by NO, NC, or COM.
--- End quote ---

Also, all Electrical Characteristics tables contains row:

--- Quote ---COM, Vno, Vnc: Analog signal range: 0 - VCC
--- End quote ---

So when Vcc is 0 all input/output should be zero.

--- Quote ---What I'm after, is that I want to know what the default state of the switch is without power applied, or if it always needs power to function.
--- End quote ---
Default state doesn't matter - output always will be 0

As I can guess this chip (as any other CMSO) has protection diodes to power rails on input/output, so when you turn off power (to high Z state) it will power itself from all NC/NO inputs (or COM, if it will be used as input)

--- End quote ---

Thanks, so how was I supposed to read that line. I just read it as 'the analog input range will between between 0 and VCC.

So if they are 'forced' to 0, that would mean, removing power would be a 'third' state, disconnected.

So why not just draw the picture like that, if vcc is off, COM is not connected to either pins?

But regardless, you answered my question, always supply power, as removing power will 'disconnect' all inputs.

MasterT:
Why not to look at TI web site?
"The VI/O pins (COM, NC, NO) can be subjected to voltages from 0V to 5.5V when the supply Vcc = 0V. "

oliv3r:

--- Quote from: MasterT on July 21, 2024, 04:27:42 pm ---Why not to look at TI web site?
"The VI/O pins (COM, NC, NO) can be subjected to voltages from 0V to 5.5V when the supply Vcc = 0V. "