Suggestion for discrete isolator between input and MCU

The current is so low. eg. the 470K limiting it, why do you care ?

To isolate you would have to open the path with a switch of some sort, like
a MOSFET or JFET.


Regards, Dana.

Hi,

as Dana says .. it is a little current. Did you calculate this current? If not, do so!
Then compare this current to the maximum allowed ESD diode current (may be named differently) of your microcontroller. You need to read it´s datatsheet.
We did not get a link to it ... for a detailed discussion, nor do we hav any information about the microcontroller.

Then you say "Before" .. what does this mean? What range of time do you speak about?
What range is VIN?

So we don´t know: timing, VIN range, microcontroller type, expected accuracy, other requirements (example: max additional current drawn from VIN and 3V3)... or whatever is important ...

**
Side information:
I expect the measurement rather inaccurate because of
* high impedance resistive divider (read microcontroller datasheet)
* I guess you "compare" against an inaccurate VCC

Klaus

danadakk said:

The current is so low. eg. the 470K limiting it, why do you care ?

To isolate you would have to open the path with a switch of some sort, like
a MOSFET or JFET.


Regards, Dana.

Click to expand...

If I use a MOSFET, I need to give the Gate control signal from the MCU, correct?

FreshmanNewbie said:

If I use a MOSFET, I need to give the Gate control signal from the MCU, correct?

Click to expand...

Yes

Prior question asked of you -

The current is so low. eg. the 470K limiting it, why do you care ?

Click to expand...