Hot plugin Protection for Controller pins

[samson.bunty1986]

Hi all,

Can anyone suggest me how to protect the controller pins when hot pluggin.

Am facing a problem like, when doing hot-plugins my analog signal pin is failing. Can anyone suggest me to protect that pins??

Am thinking to put a low reverse breakdown voltage diode in parallel with that sensing pin to ground. Will this protect my analog pin??

My analog sense pin voltage is 3.3V. Can i put a diode in parallel?? Or any other protective components??

Kindly suggest me what to do?? Thanks in advance.

Regards,
Samson

 

[BeerBelly]

What kind if analog device is plugging into the controller?

 

[schmitt trigger]

My experience with failures during hot plugins indicate that what happens is that the signal pins mate before the ground actually mates. That despite the pins having extensive protections.

If you are familiar with the loud noise created when one plugs-unplugs an electric guitar into an amp. well that is precisely what happens.

The problem (for ourselves) was a ground pin which was longer than the other pins, which would ensure that ground was always there before any signals

 

[alec_t]

Depending on your analog signal source and your analog input spec you may be able to use an RC filter to damp rapid voltage changes at the pin.

 

[KeepItSimpleStupid]

Do some searcing on "hot swap controllers". Here is just one example: https://www.maximintegrated.com/app-notes/index.mvp/id/2736

 

[samson.bunty1986]

Whenever we are HOT plugging my analog sensing pin and ground is almost getting short(Low resistance). So analog sensing pin gets failed. I dont want to use an external ic. Need suggestion is any possibility of using passive components. in series or parallel to analog pin to protect the Analog pin.

 

[KeepItSimpleStupid]

Can you post the particulars (schematic) of the two hot and cold parts?

 

[samson.bunty1986]

Here is the particulars of that analog pin. Check out the protection diode circuit. can this is effecting the sensing pin.

 

[KeepItSimpleStupid]

Can't find a diode nor can figure out what pins are mating.

 

[samson.bunty1986]

The picture which i have sent is not clear?? we are using DALC2028

 

[alec_t]

Google doesn't seem to have heard of that part number. Can you post a link to its datasheet?

Edit: What is the maximum specified source impedance for the analogue input of your controller? A simple series resistor to that input may be all that's necessary if you don't exceed that spec.

 

[samson.bunty1986]

Srry..the part number is DALC208SC..

 

[ChrisP58]

Is the DALC208SC the part that is failing, or is it what you are trying to use to protect the analog part?

What is the part that is failing, and what is the rest of it's circuit? Is that component alone that is being hot plugged, or is it on a board that you are hot plugging?

 

[samson.bunty1986]

Hi Chris,

We are using that DALC ic for ESD protection at analog pin. Failing is happening at that pin only. remaining analog section is good. Only individual pin is failing. We are using only one analog pin. That pin only failing. We dont know whether it is failing because the DALC ic is failing. Kindly suggest me how to protect that individual pin other than DALC ic. Hot plugin is on board.

 

[alec_t]

You haven't answered the impedance question in post #11.