[Moved] ESD diode check for analog switch, value measured need to be understand

[arunmaran10]

Hi All
I have analog switch in my board, when i do ESD diode check the value i am getting is around .3 to .4v for NXP switch(even this is decreasing when i hold it for some time).
What would be the reason would be.


Thanks and Regards,
Arunmaran

 

[crutschow]

Reason for what?

 

[dick_freebird]

Maybe a big diode, maybe a Schottky diode, maybe your test
conditions and limits are all made up by you irrespective of
the realities of the product design, maybe there is a shunt
elsewhere on the trace.

For starters.

 

[Borber]

Temperature coefficient can be the reason. It is usually negative. ESD checks must be done with short pulse to avoid heating of diode.

 

[arunmaran10]

Maybe a big diode, maybe a Schottky diode, maybe your test
conditions and limits are all made up by you irrespective of
the realities of the product design, maybe there is a shunt
elsewhere on the trace.

For starters.

WHAT IS THE LAST POINT SAYS SHUNT ELSE WHERE ON THE TRACE, CAN YOU PLEASE EXPLAIN BRIEFLY.

Thanks and Regards,
Arunmaran

- - - Updated - - -

Reason for reducing value when i do diode check for the switch. decreasing when i keep on holding negative to switch pad and positive to the ground

 

[dick_freebird]

You say the switch is in your board. That implies that there
are connections to it. Those connections might affect the
readings - for example, maybe somebody put Schottky clamps
at the input connector the switch connects to (or something).