Protection Circuit for Switch

[jimmykk]

Hi all

I have designed a PCB where I am using ADG1636BRUZ SPDT Switch at +/-5V Supply Voltage to connect to my 5 piezoelectric transducers.

The motive of the design is to select one of the transducers (connected at connectors P1-P5 ) at a time and run some measurements. These piezoelectric transducers are submerged in water and can carry several hundred Volts in them.

Schematics is described as follows:

3x ADG1636 Switches are used. These switches are used to connect one by one to the 5 transducers(i.e. 2 transducers with each switch). The problem with the design is that these Switches get damaged after some use which I suspect is due to the voltage coming from the transducers as there is no protection between connectors and these switches.

So, wondering if I can put any protection circuit between these ICs and connectors to save them from burning out. Would placing some protection diodes be a solution. If yes, what are the options?

 

[KlausST]

Hi

Schematics is described as follows:

A picture tells more than a lot of words.
Please post your schematic as a .PNG.
Also IC fail may come from unsuitable PCB layout. Thus it´s a god idea to show us your PCB layout.

ICs get damaged by:
* overvoltage
* overcurrent
* overheat (short time or ling time)

You first have to find out what causes the damage, then yu can choos a suitable protection circuit.

Klaus

 

[jimmykk]

Here is the Schematics(Attached).
ADG1604 are the multiplexers(having Input at Pin6, Output Pins 4,5,10,11) used to send the signal to the transducers.
Pretty sure the fault lies in the Schematics than layout. Transducers are quite big and can hold a lot of charge.